Strumming the guitar
A term meaning sex and/or hand jobs, depending on how it is used. If someone offers you a guitar lesson, it means they are offering you sex or some "strum fun". During the guitar lesson analogy, condoms are referred to as pleactrums.
Person one: Hey, fancy meeting my in the music cupboard later for a... guitar lesson? I fancy strumming the guitar ;)
Person two: No sorry, no strum fun for my today, I don't have a plectrum on me.
Person two: No sorry, no strum fun for my today, I don't have a plectrum on me.
Strumming the meat guitar
Female Masturbation
I caught my mum strumming the meat guitar last night
Strumming the flesh guitar
synonym: Fapping - The art of making love to yourself
Daniella went home to for a session strumming the flesh guitar