A sexual act preformed in group sex. This occurs when the male directs multiple women to lay on top of each other so he can proceed to have 'doggie-style' sex with them with minimal transitional effort. The reasoning for including 'Salt Lake City' in the name of the act is mainly because, Salt Lake City, UT has a Mormon population of roughly 60%, thus explaining the polygamy joke.
Alex: Did you ever end out seeing Semen Sippers 5?

Max: Yeah, that guy got Jenna Haze and Lela Star to do the ol' Salt Lake City Stack about twenty minutes in, it was flossy.
by ckboarder May 7, 2009
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