A pulled-pork sandwich is where one man inserts his penis in another man's rectum. The pulled-pork refers to the penis (which at one point or another may have been pulled to aid in getting an erection) while the "buns" are referring to the pulled-pork sandwich recipient's buttocks. It is essentially a euphemism for anal sex.

when you're hungover as shit after a spending a night drunk as a skunk

When three cops sit in a row and the outside two jerk off the middle one.

A vicious prank requiring two pranksters and requiring the target to be nude (most likely a locker room shower). Prankster A pulls on the target’s penis. While the target is distracted, prankster B claps on the target’s testicles.

A pulled pork sandwich is when a girls pussy resembles pulled pork and her camel toe resembles two sesame seed buns hints the name pulled pork sandwich. It is even more so like a pulled pork sandwich if she is having her period and the blood would resemble the BBQ sauce.

When you slather barbeque sauce on your penis and use it as lubricant while you have anal sex, then when you reach completion, ejaculate in between your partner's butt cheeks.