Female version of the rusty trombone, where a woman bends over allowing a guy or girl to tongue the woman's anus while reaching up through her legs and fingering her clitoris.
All Beth has to do is bend over and say, "Time to play that rusty accordion."
When a dude tries to penetrate and girls cunt with his dick and it folds up like an accordion.
Most likely the guy is drunk or really high before the phenomenon. After you accordion dick a girl, the guy has to yell, "You've been accordion dicked, bitch!" Then the sweet-ass-dude has to bellow like an accordion, "Whoooom!"