The act of performing anilingus on one's girlfriend and simultaneously reaching around to stimulate her vaginal area by hand. Term derived from the "rusty trombone" as women are not equipped with a trombone-like appendage; moreover the originator of the term maintains that while they do not know how to play the autoharp, the term merely sounds hilarious.
Kenny was going down on me last night, then went to the back door and gave me a rusty autoharp!
Buy a
Rusty Autoharp
mug!
