Sucking Hind Titty
1.In the animal kingdom, the runt of the litter gets stuck with the tit closest to the ass of the animal. Which has the least amount of milk in it.Therefore the meaning has evolved into human terms as to get the shitty end of the stick, to get leftoversor to be the last in line.
Alvin was in on the gang bang but he ended up Sucking Hind Titty.