88 Choo-Choo Train
A group sex activity where four males use their penises to form a cross around a female's breasts and the female uses her feet, mouth, and one ear to stimulate male ejaculation from all four parties.
Carolee: How drunk was I last night?

Collin: You, me, and three of my buds all got into an 88 Choo-Choo Train, it was awesome.

Carolee: Is that why my ear hurts?