Trashbarging is preciselythe same as motorboating, except for the fact that when trashbarging the trashbarger places their face in the cleavage of the trashbargees ass, rather than their breasts.
I met this girl named Boston at the bar the other night and bought her a few drinks... By the end of the night, I was trashbarging Boston's harbor!
When a person (usually a female) does something really trashy and is not only proud of it but brags about it like it's the greatestachievement of their life.