Kevin was very happy: he was just about to stick his bacon bazooka into Britney's rattle bollocks, but then he woke up and was disappointed to find it was just Peggy in bed with him.
It is a combination of the word titties and rolls. Most common among portly women. When there's no distinction between the rolls of fat that run a long their sides and their breasts.
Zack: Damn! That girl may be portly but she has some huge knockers!
Joe: Yeah your right! Oh wait. The're just ritties.