-To go to a friends house and compare penises/ touch your penis/each others penises.
-To go to a friends house to hang around and and occasionally play Lego Batman, Lego Indy Lego StarWars and Lego.
Person A: wanna go play willies
Person B: yeah im gonna kick yo ass with the joker.
Person C: can i come?
Person B: Yeah but you have to be Bat Girl.
Person C: I love playing willies
Person A: Your just gay.