A three way sex act involving at least one male who inserts his penis into the anus of both other participants.
I picked up two girls at the bar last night and took them home and got a Hershey double dip.
A sexual act involving three people, of which at least one is a male, wherein two of the threesome are anally penetrated by the third.
I picked up two chicks at the bar and they took me home and let me give them a Hershey double dip.