Slippery Dolphin
When you and a girl drunk as hell in the bathtub or jacuzzi with a chick that you know doesn't like anal and try to have anal sex with her. She shakes her head and makes sounds like a dolphin would as you try to stick it in her ass. "Ahhkaa Ahhkaa Ahhka" like a dolphin, hence the slippery dolphin!
"I tried the slippery dolphin with that drunk hoe last night but she wouldn't let me!"
Slippery Dolphin
The act of pulling out while doing doggie style, cumming into your open palm, and slapping your partner in the face.
Bro I pulled the slippery dolphin on Jennifer last night. Her face was red and swollen for hours!
slippery dolphin
When a guy is fucking his girl from behind and his dick slips out and accidentally penetrates her anus causing her to arch her back and scream "eeeeet, eeeet, eeeet!"
That porpoise noise coming from the bedroom last night must've been mom getting a slippery dolphin from dad!