quiet night
Basically when you ask someone if they're coming out or online with you and they say they're having one of these. There's no other way to put it; they're masturbating.
Person 1: Hey, you wanna play some games later on?
Person 2: Nah, I'm having a quiet night tonight.
Person 1: Have fun... ( ͡° ͜ʖ ͡°)
Person 2: Nah, I'm having a quiet night tonight.
Person 1: Have fun... ( ͡° ͜ʖ ͡°)