a rusty trombone except the "mouthpiece" is exceptionally dirty
she was sure in for a surpise when i hadn't wiped in a few days, and she played the crusty trombone.
by hot karl August 11, 2003
An act of love between two men, where one male ejactulates on the butthole/crack of the other after anal intercourse. The semen is then allowed to dry, after which a standard 'rusty trombone' is performed on the newly dried 'crusty' asshole.
After he reemed my cornhole, he gave me a nice crusty trombone which not only gave me phallic pleasure, but soothed my sore asshole.
by Joe Riggidy January 13, 2009