Damn! I had to read 53 WRONG definitions of the RUSTY TROMBONE! It has nothing to do with gay dudes, reach arounds, or assholes. It's when you fuck a chick ON HER PERIOD, then she immediatly blows you. Blood has a distinct taste that can well be described as...rusty.
Guy#1: Yeah, so did you hear Blake was dating that weird, goth, "Twilight" chick?
Guy#2: Hey, I bet he gets the old rusty trombone no sweat.