sham

slang for self-stimulation; acronym for Stay Home And Masturbate; generally used as an excuse when one does not want to participate in social activities/events. Can also be used to as a synonym for masturbation, regardless of whether or not the subject actually stayed home.

"Hey Nadia, we're going to Shenanigans tonight, you coming?"
"Nah, I'm not really feeling it tonight. Think I'm just gonna sham."

"That sext you sent me was so hot that I just had to sham."

"I shammed last night."