A novelty shot, typically served to an unsuspecting victim as either a gag or as punishment for turning 21. To make the shot, one first fills a rocks glass with house vodka, and then proceeds to suck up a small amount of milk with a straw, lowers the end of the straw into the bottom of the glass, and slowly releases the milk while pulling the straw up and out, with the end result resembling semen being suspended in the water of the hot tub, thus you have the sex in a hot tub.
Bro 1: Happy Birthday bro, I bought you a shot!

Bro 2: Thanks bro, what is it?

Bro 1: Its a sex in a hot tub, now shut up and drink it!

Bro 2: (gulp)

Bro 1: That's what you get for turning 21!
by mason-dixon-line August 16, 2011
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