I have decided that this is the time for my revenge. My boyfriend is going to wear his favorite big sweater and I'm going to get him messy.
Give me your ideas for ingredients or what substance to use to mess and humiliate him

HA! You can't go wrong with copious amounts of chocolate. Just look at my profile photo. LOL!

Pie, pie, pie, and more pie. Pie in his face and down his shirt and pants. Chocolate syrup, gallons of it, over his head, down his pants and down his shirt. More pies. A fountain of maple syrup down the front of his sweater and down into his pants.

Maple Syrup, Honey, and Caramel Syrup either together makes for a godawfully sticky situation so maybe do that as a nice starter then pile all the pies and other mess on so even once he washes all that mess off, it'll take another shower or two to remove the stickiness. Trust me I know

Pies and sticky mess....l love that

Thick bucket of Gunge over head then down his pants.

Some banana cream pies, chocolate pies, and key lime pies to the face, and slime him with spaghetti, and chocolate.

Sweet revenge
my girlfriend will have to pay for what she just did to me

I have other sweaters, I am open to your messy suggestions. I am waiting for your suggestions

Very deserved!

But I want to see you get the girlfriend first. How about a big, 5-gallon bucket of chcoolate sauce poured over her head as she sits in a chair. HA!