A Penis Butter and Jelly sandwich is when a guy cums in a girls vagina when shes on her period and there is a mixure of blood and jizz oozing from her slot. Her vag flaps supposedly being bread
A sandwich comprised of Penis Butter (Sperm, Semen, Ejaculate, Cum, Baby Gravy, Baby Batter, Horny Muffins, Knob Slime, Peace Grease, Dick Goo, Ectoplasm of The Nether, Spoofs...etc.) and the popular personal lubricant K.Y. Jelly. Often said as a joke or sang in substitution of the old "Peanut Butter and Jelly " song features on the 90's popular kids TV show Barney the Dinosaur.
Example of a joke with a friend if they don't like something.: (See Example Below)
Other example: look up Barney Peanut butter and Jelly and change the words, you will see where the idea came from.
"Wow, why don't you just go and eat a Penis Butter and K.Y. Jelly Sandwich!?"
When you pull out and evenly distribute your load across the girl’s stomach, then jump on top of her and squirm around while yelling, “Peanut butter jelly! Peanut butter jelly!”
Me: Yo that chick I banged last night won’t text me back.
Bud: Wtf did you do?
Me: I don’t know, maybe she didn’t like the penis butter belly sandwich I made for her.
When a guy ejaculates into a girls held-together thighs with the head of his dick nestled between her legs, instead of jizzing in her vagina or upon her stomach.
Hey what happened last night?
Man we ran out of condoms so i justgave her a penis butter samwich.