diff --git a/components/ideas/idea-detail-layout.tsx b/components/ideas/idea-detail-layout.tsx
index 4b962d9..e8e3916 100644
--- a/components/ideas/idea-detail-layout.tsx
+++ b/components/ideas/idea-detail-layout.tsx
@@ -20,7 +20,7 @@ import { getIdeaStatusBadge } from '@/lib/idea-status-colors'
 import type { IdeaStatusApi } from '@/lib/idea-status'
 import { isIdeaEditable } from '@/lib/idea-status'
 import type { IdeaDto } from '@/lib/idea-dto'
-import { updateIdeaAction, archiveIdeaAction } from '@/actions/ideas'
+import { updateIdeaAction, archiveIdeaAction, updateSecondaryProductsAction } from '@/actions/ideas'
 import { IdeaRowActions } from '@/components/ideas/idea-row-actions'
 import { IdeaMdEditor } from '@/components/ideas/idea-md-editor'
 import { IdeaPbiLinkCard } from '@/components/ideas/idea-pbi-link-card'
@@ -163,6 +163,18 @@ export function IdeaDetailLayout({
               <span className="text-sm italic text-muted-foreground">geen product</span>
             )}
           </div>
+          {idea.secondary_products.length > 0 && (
+            <div className="flex flex-wrap gap-1 mt-1">
+              {idea.secondary_products.map((sp) => (
+                <span
+                  key={sp.id}
+                  className="text-xs bg-muted px-2 py-0.5 rounded-full text-muted-foreground"
+                >
+                  {sp.product.name}
+                </span>
+              ))}
+            </div>
+          )}
         </div>
         <IdeaRowActions idea={idea} isDemo={isDemo} onArchive={handleArchive} />
       </header>
@@ -214,6 +226,7 @@ export function IdeaDetailLayout({
           products={products}
           isDemo={isDemo}
           pending={pending}
+          secondaryProducts={idea.secondary_products}
         />
       )}
       {tab === 'grill' && (
@@ -250,9 +263,10 @@ interface FormProps {
   products: ProductOption[]
   isDemo: boolean
   pending: boolean
+  secondaryProducts: IdeaDto['secondary_products']
 }
 
-function IdeaFormSection({ idea, products, isDemo, pending }: FormProps) {
+function IdeaFormSection({ idea, products, isDemo, pending, secondaryProducts }: FormProps) {
   const router = useRouter()
   const editable =
     !isDemo &&
@@ -260,12 +274,20 @@ function IdeaFormSection({ idea, products, isDemo, pending }: FormProps) {
   const [title, setTitle] = useState(idea.title)
   const [description, setDescription] = useState(idea.description ?? '')
   const [productId, setProductId] = useState(idea.product_id ?? '')
+  const [selectedSecondary, setSelectedSecondary] = useState<string[]>(
+    secondaryProducts.map((sp) => sp.product_id),
+  )
   const [submitting, startSubmit] = useTransition()
 
+  const secondaryDirty =
+    JSON.stringify([...selectedSecondary].sort()) !==
+    JSON.stringify(secondaryProducts.map((sp) => sp.product_id).sort())
+
   const dirty =
     title !== idea.title ||
     description !== (idea.description ?? '') ||
-    productId !== (idea.product_id ?? '')
+    productId !== (idea.product_id ?? '') ||
+    secondaryDirty
 
   function save() {
     startSubmit(async () => {
@@ -278,6 +300,13 @@ function IdeaFormSection({ idea, products, isDemo, pending }: FormProps) {
         toast.error(r.error)
         return
       }
+      if (secondaryDirty) {
+        const r2 = await updateSecondaryProductsAction(idea.id, selectedSecondary)
+        if ('error' in r2) {
+          toast.error(r2.error)
+          return
+        }
+      }
       toast.success('Opgeslagen')
       router.refresh()
     })
@@ -320,6 +349,30 @@ function IdeaFormSection({ idea, products, isDemo, pending }: FormProps) {
           ))}
         </select>
       </div>
+      {products.filter((p) => p.id !== productId).length > 0 && (
+        <div className="space-y-1">
+          <label className="text-xs font-medium text-muted-foreground">Extra producten</label>
+          <div className="space-y-1">
+            {products
+              .filter((p) => p.id !== productId)
+              .map((p) => (
+                <label key={p.id} className="flex items-center gap-2 text-sm">
+                  <input
+                    type="checkbox"
+                    checked={selectedSecondary.includes(p.id)}
+                    onChange={(e) =>
+                      setSelectedSecondary((prev) =>
+                        e.target.checked ? [...prev, p.id] : prev.filter((id) => id !== p.id),
+                      )
+                    }
+                    disabled={!editable || pending || submitting}
+                  />
+                  {p.name}
+                </label>
+              ))}
+          </div>
+        </div>
+      )}
 
       {!editable && (
         <p className="text-xs text-muted-foreground italic">
@@ -337,6 +390,7 @@ function IdeaFormSection({ idea, products, isDemo, pending }: FormProps) {
               setTitle(idea.title)
               setDescription(idea.description ?? '')
               setProductId(idea.product_id ?? '')
+              setSelectedSecondary(secondaryProducts.map((sp) => sp.product_id))
             }}
           >
             Reset