diff --git a/api/src/graphql/partReactions.sdl.js b/api/src/graphql/partReactions.sdl.js
index 7aba11f..4eaaa26 100644
--- a/api/src/graphql/partReactions.sdl.js
+++ b/api/src/graphql/partReactions.sdl.js
@@ -15,7 +15,7 @@ export const schema = gql`
     partReaction(id: String!): PartReaction
   }
 
-  input CreatePartReactionInput {
+  input TogglePartReactionInput {
     emote: String!
     userId: String!
     partId: String!
@@ -28,7 +28,7 @@ export const schema = gql`
   }
 
   type Mutation {
-    createPartReaction(input: CreatePartReactionInput!): PartReaction!
+    togglePartReaction(input: TogglePartReactionInput!): PartReaction!
     updatePartReaction(
       id: String!
       input: UpdatePartReactionInput!
diff --git a/api/src/graphql/parts.sdl.js b/api/src/graphql/parts.sdl.js
index 917ca7b..a7f42e4 100644
--- a/api/src/graphql/parts.sdl.js
+++ b/api/src/graphql/parts.sdl.js
@@ -10,7 +10,7 @@ export const schema = gql`
     user: User!
     userId: String!
     Comment: [Comment]!
-    Reaction: [PartReaction]!
+    Reaction(userId: String): [PartReaction]!
   }
 
   type Query {
diff --git a/api/src/lib/owner.js b/api/src/lib/owner.js
index e52ac90..086deeb 100644
--- a/api/src/lib/owner.js
+++ b/api/src/lib/owner.js
@@ -1,4 +1,4 @@
-import { AuthenticationError, ForbiddenError, parseJWT } from '@redwoodjs/api'
+import { AuthenticationError, ForbiddenError } from '@redwoodjs/api'
 import { db } from 'src/lib/db'
 
 export const requireOwnership = async ({ userId, userName, partId } = {}) => {
diff --git a/api/src/services/partReactions/partReactions.js b/api/src/services/partReactions/partReactions.js
index e7b526d..4efd545 100644
--- a/api/src/services/partReactions/partReactions.js
+++ b/api/src/services/partReactions/partReactions.js
@@ -1,3 +1,7 @@
+import { UserInputError } from '@redwoodjs/api'
+
+import { requireAuth } from 'src/lib/auth'
+import { requireOwnership } from 'src/lib/owner'
 import { db } from 'src/lib/db'
 import { foreignKeyReplacement } from 'src/services/helpers'
 
@@ -11,10 +15,26 @@ export const partReaction = ({ id }) => {
   })
 }
 
-export const createPartReaction = ({ input }) => {
-  return db.partReaction.create({
-    data: foreignKeyReplacement(input),
-  })
+export const togglePartReaction = async ({ input }) => {
+  // if write fails emote_userId_partId @@unique constraint, then delete it instead
+  requireAuth()
+  await requireOwnership({userId: input?.userId})
+  const legalReactions = ['❤️', '👍', '😄', '🙌'] // TODO figure out a way of sharing code between FE and BE, so this is consistent with web/src/components/EmojiReaction/EmojiReaction.js
+  if(!legalReactions.includes(input.emote)) {
+    throw new UserInputError(`You can't react with '${input.emote}', only the following are allowed: ${legalReactions.join(', ')}`)
+  }
+  let dbPromise
+  const inputClone = {...input} // TODO foreignKeyReplacement mutates input, which I should fix but am lazy right now
+  try{
+    dbPromise = await db.partReaction.create({
+      data: foreignKeyReplacement(input),
+    })
+  } catch(e) {
+    dbPromise = db.partReaction.delete({
+      where: { emote_userId_partId: inputClone},
+    })
+  }
+  return dbPromise
 }
 
 export const updatePartReaction = ({ id, input }) => {
diff --git a/api/src/services/parts/parts.js b/api/src/services/parts/parts.js
index 8589c5e..017ad9c 100644
--- a/api/src/services/parts/parts.js
+++ b/api/src/services/parts/parts.js
@@ -57,5 +57,5 @@ export const Part = {
   Comment: (_obj, { root }) =>
     db.part.findOne({ where: { id: root.id } }).Comment(),
   Reaction: (_obj, { root }) =>
-    db.part.findOne({ where: { id: root.id } }).Reaction(),
+    db.part.findOne({ where: { id: root.id } }).Reaction({where: {userId: _obj.userId}}),
 }
diff --git a/web/src/components/EmojiReaction/EmojiReaction.js b/web/src/components/EmojiReaction/EmojiReaction.js
index b90151d..722aa06 100644
--- a/web/src/components/EmojiReaction/EmojiReaction.js
+++ b/web/src/components/EmojiReaction/EmojiReaction.js
@@ -13,7 +13,7 @@ const noEmotes =[{
 
 const textShadow = {textShadow: '0 4px 6px rgba(0, 0, 0, 0.3)'}
 
-const EmojiReaction = ({ emotes, onEmote = () => {}, className }) => {
+const EmojiReaction = ({ emotes, userEmotes, onEmote = () => {}, className }) => {
   const [isOpen, setIsOpen] = useState(false)
   const [anchorEl, setAnchorEl] = useState(null)
   const [popoverId, setPopoverId] = useState(undefined)
@@ -59,7 +59,10 @@ const EmojiReaction = ({ emotes, onEmote = () => {}, className }) => {
         <div className="whitespace-no-wrap absolute right-0 inset-y-0 flex items-center flex-row-reverse">
           {(emotes.length ? emotes : noEmotes).map((emote, i) => (
             <span
-              className="rounded-full tracking-wide hover:bg-indigo-100 p-1 mx-px transform hover:-translate-y-px transition-all duration-150"
+              className={getActiveClasses(
+                "rounded-full tracking-wide hover:bg-indigo-100 p-1 mx-px transform hover:-translate-y-px transition-all duration-150 border-indigo-400",
+                {'border': userEmotes.includes(emote.emoji)}
+              )}
               style={textShadow}
               key={`${emote.emoji}--${i}`}
               onClick={() => handleEmojiClick(emote.emoji)}
diff --git a/web/src/components/NewPartReaction/NewPartReaction.js b/web/src/components/NewPartReaction/NewPartReaction.js
index 8cbcba3..07457d2 100644
--- a/web/src/components/NewPartReaction/NewPartReaction.js
+++ b/web/src/components/NewPartReaction/NewPartReaction.js
@@ -3,8 +3,8 @@ import { navigate, routes } from '@redwoodjs/router'
 import PartReactionForm from 'src/components/PartReactionForm'
 
 const CREATE_PART_REACTION_MUTATION = gql`
-  mutation CreatePartReactionMutation($input: CreatePartReactionInput!) {
-    createPartReaction(input: $input) {
+  mutation TogglePartReactionMutation($input: TogglePartReactionInput!) {
+    togglePartReaction(input: $input) {
       id
     }
   }
@@ -12,7 +12,7 @@ const CREATE_PART_REACTION_MUTATION = gql`
 
 const NewPartReaction = () => {
   const { addMessage } = useFlash()
-  const [createPartReaction, { loading, error }] = useMutation(
+  const [togglePartReaction, { loading, error }] = useMutation(
     CREATE_PART_REACTION_MUTATION,
     {
       onCompleted: () => {
@@ -23,7 +23,7 @@ const NewPartReaction = () => {
   )
 
   const onSave = (input) => {
-    createPartReaction({ variables: { input } })
+    togglePartReaction({ variables: { input } })
   }
 
   return (
diff --git a/web/src/components/Part2Cell/Part2Cell.js b/web/src/components/Part2Cell/Part2Cell.js
index 4dcff89..005d58e 100644
--- a/web/src/components/Part2Cell/Part2Cell.js
+++ b/web/src/components/Part2Cell/Part2Cell.js
@@ -1,10 +1,11 @@
 import { useMutation, useFlash } from '@redwoodjs/web'
 import { navigate, routes } from '@redwoodjs/router'
+import { useAuth } from '@redwoodjs/auth'
 
 import PartProfile from 'src/components/PartProfile'
 
 export const QUERY = gql`
-  query FIND_PART_BY_USERNAME_TITLE($userName: String!, $partTitle: String!) {
+  query FIND_PART_BY_USERNAME_TITLE($userName: String!, $partTitle: String!, $currentUserId: String!) {
     userPart: userName(userName: $userName) {
       id
       name
@@ -20,6 +21,12 @@ export const QUERY = gql`
         createdAt
         updatedAt
         userId
+        Reaction {
+          emote
+        }
+        userReactions: Reaction(userId: $currentUserId) {
+          emote
+        }
       }
     }
   }
@@ -37,6 +44,14 @@ const UPDATE_PART_MUTATION = gql`
     }
   }
 `
+const TOGGLE_REACTION_MUTATION = gql`
+  mutation ToggleReactionMutation($input: TogglePartReactionInput!) {
+    togglePartReaction(input: $input){
+      id
+      emote
+    }
+  }
+`
 
 export const Loading = () => <div>Loading...</div>
 
@@ -44,7 +59,8 @@ export const Empty = () => <div>Empty</div>
 
 export const Failure = ({ error }) => <div>Error: {error.message}</div>
 
-export const Success = ({ userPart, variables: {isEditable} }) => {
+export const Success = ({ userPart, variables: {isEditable}, refetch}) => {
+  const { currentUser } = useAuth()
   const { addMessage } = useFlash()
   const [updateUser, { loading, error }] = useMutation(UPDATE_PART_MUTATION, {
     onCompleted: ({updatePart}) => {
@@ -52,16 +68,25 @@ export const Success = ({ userPart, variables: {isEditable} }) => {
       addMessage('Part updated.', { classes: 'rw-flash-success' })
     },
   })
-
   const onSave = (id, input) => {
     updateUser({ variables: { id, input } })
   }
 
+  const [toggleReaction] = useMutation(TOGGLE_REACTION_MUTATION, {
+    onCompleted: (hey) => refetch()
+  })
+  const onReaction = (emote) => toggleReaction({variables: {input: {
+    emote,
+    userId: currentUser.sub,
+    partId: userPart?.Part?.id,
+  }}})
+
   return <PartProfile
     userPart={userPart}
     onSave={onSave}
     loading={loading}
     error={error}
     isEditable={isEditable}
+    onReaction={onReaction}
   />
 }
diff --git a/web/src/components/PartProfile/PartProfile.js b/web/src/components/PartProfile/PartProfile.js
index f0b2390..9a43d94 100644
--- a/web/src/components/PartProfile/PartProfile.js
+++ b/web/src/components/PartProfile/PartProfile.js
@@ -7,11 +7,14 @@ import ImageUploader from 'src/components/ImageUploader'
 import Breadcrumb from 'src/components/Breadcrumb'
 import EmojiReaction from 'src/components/EmojiReaction'
 import Button from 'src/components/Button'
+import { countEmotes } from 'src/helpers/emote'
 
-const PartProfile = ({userPart, isEditable, onSave, loading, error}) => {
+const PartProfile = ({userPart, isEditable, onSave, loading, error, onReaction}) => {
   const { currentUser } = useAuth()
   const canEdit = currentUser?.sub === userPart.id
   const part = userPart?.Part
+  const emotes = countEmotes(part?.Reaction)
+  const userEmotes = part?.userReactions.map(({emote}) => emote)
   useEffect(() => {isEditable &&
     !canEdit &&
     navigate(routes.part2({userName: userPart.userName, partTitle: part.title}))},
@@ -50,12 +53,10 @@ const PartProfile = ({userPart, isEditable, onSave, loading, error}) => {
           />
           <h4 className="text-indigo-800 text-xl underline text-right py-4">{userPart?.name}</h4>
           <div className="h-px bg-indigo-200 mb-4" />
-          {/* TODO hook up to emoji data properly */}
           <EmojiReaction
-            // emotes={[{emoji: '❤️',count: 3},{emoji: '😁',count: 2},{emoji: '😜',count: 2},{emoji: '🤩',count: 2},{emoji: '🤣',count: 2},{emoji: '🙌',count: 2},{emoji: '🚀',count: 2}]}
-            emotes={[{emoji: '❤️',count: 3},{emoji: '😁',count: 2}]}
-            // emotes={[]}
-            onEmote={() => {}}
+            emotes={emotes}
+            userEmotes={userEmotes}
+            onEmote={onReaction}
           />
           <Button
             className="mt-6 ml-auto hover:shadow-lg bg-gradient-to-r from-transparent to-indigo-100"
diff --git a/web/src/components/Parts/Parts.js b/web/src/components/Parts/Parts.js
index 71719b6..84c9422 100644
--- a/web/src/components/Parts/Parts.js
+++ b/web/src/components/Parts/Parts.js
@@ -1,17 +1,10 @@
-import { useMemo } from 'react'
 import { Link, routes } from '@redwoodjs/router'
 
+import { countEmotes } from 'src/helpers/emote'
 import ImageUploader from 'src/components/ImageUploader'
+
 const PartsList = ({ parts }) => {
-  const countEmotes = (reactions) => {
-    // would be good to do this sever side
-    // counting unique emojis, and limiting to the 5 largest
-    const emoteCounts = {}
-    reactions.forEach(({emote}) => {
-      emoteCounts[emote] = emoteCounts[emote] ? emoteCounts[emote] + 1 : 1
-    })
-    return Object.entries(emoteCounts).map(([emoji, count]) => ({emoji, count})).sort((a,b) => a.count-b.count).slice(-5)
-  }
+
   return (
     <section className="max-w-6xl mx-auto mt-20">
       <ul className="grid gap-x-8 gap-y-12 items-center mx-4 relative" style={{gridTemplateColumns: 'repeat(auto-fit, minmax(16rem, 1fr))'}}>
diff --git a/web/src/helpers/emote.js b/web/src/helpers/emote.js
new file mode 100644
index 0000000..fd80382
--- /dev/null
+++ b/web/src/helpers/emote.js
@@ -0,0 +1,10 @@
+export const countEmotes = (reactions) => {
+  // would be good to do this sever side
+  // counting unique emojis, and limiting to the 5 largest
+  const emoteCounts = {}
+  reactions.forEach(({emote}) => {
+    emoteCounts[emote] = emoteCounts[emote] ? emoteCounts[emote] + 1 : 1
+  })
+  // TODO the sort is causing the emotes to jump around after the user clicks one, not ideal
+  return Object.entries(emoteCounts).map(([emoji, count]) => ({emoji, count})).sort((a,b) => a.count-b.count).slice(-5)
+}
diff --git a/web/src/pages/EditPart2Page/EditPart2Page.js b/web/src/pages/EditPart2Page/EditPart2Page.js
index 25bf0ee..7481b6f 100644
--- a/web/src/pages/EditPart2Page/EditPart2Page.js
+++ b/web/src/pages/EditPart2Page/EditPart2Page.js
@@ -1,10 +1,18 @@
+import { useAuth } from '@redwoodjs/auth'
+
 import MainLayout from 'src/layouts/MainLayout'
 import Part2Cell from 'src/components/Part2Cell'
 
 const EditPart2Page = ({userName, partTitle}) => {
+  const { currentUser } = useAuth()
   return (
     <MainLayout>
-      <Part2Cell userName={userName} partTitle={partTitle} isEditable/>
+      <Part2Cell
+        userName={userName}
+        partTitle={partTitle}
+        currentUserId={currentUser.sub}
+        isEditable
+      />
     </MainLayout>
   )
 }
diff --git a/web/src/pages/Part2Page/Part2Page.js b/web/src/pages/Part2Page/Part2Page.js
index 6b4e752..03b80e6 100644
--- a/web/src/pages/Part2Page/Part2Page.js
+++ b/web/src/pages/Part2Page/Part2Page.js
@@ -1,10 +1,17 @@
+import { useAuth } from '@redwoodjs/auth'
+
 import MainLayout from 'src/layouts/MainLayout'
 import Part2Cell from 'src/components/Part2Cell'
 
 const Part2Page = ({userName, partTitle}) => {
+  const { currentUser } = useAuth()
   return (
     <MainLayout>
-      <Part2Cell userName={userName} partTitle={partTitle}/>
+      <Part2Cell
+        userName={userName}
+        partTitle={partTitle}
+        currentUserId={currentUser.sub}
+      />
     </MainLayout>
   )
 }