flute solo 

To masturbate without saying it with the exact words

"When I get home I'm gonna do a flute solo

flute solo by Bra21gottem April 15, 2015

playing the flute solo 

A euphemism for masturbating.

Girl: Got any plans for tonight?
Guy: Not much, probably just playing the flute solo, if you know what I mean.
Girl: Want to make it a duet?

playing the flute solo by "Nasty" Nate April 5, 2008