A situation in which two females who, for whatever reason, end up sharing a single cocktail for most of the evening (More than likely to save money since most bitches are worthless).
In this instance, a desperate male carefully places rohypnol or another date rape drug in the shared drink while either female is distracted by some sort of shiny object. The consequent result being the unmistakable & urgent need for both females to suddenly enjoy "sleepy time."
This opportunity is often exploited by said pathetic male in order to indulge in sexual activity with not only one, but two unsuspecting female subjects at once, which would otherwise be impossible for such a man, who is so regularly deemed a socially unacceptable mate & typically doomed to rely on internet porn for female companionship.
Damn, bro! I can't believe you came here with only $2 & still managed to pull off a Roofer Twofer without gettin caught... You're such a SlagMagnet!!!