Robin's Mask
When you straddle your (ideally, much younger) boyfriend and pull a batwing {stretching ones' scrotum until it resembles a bat's wing} over his eyes.
To get the part, Joseph Gordon-Levitt let Christopher Nolan give him a Robin's Mask
Batgirl's Wing Batwing Electrolysis Ben Affleck Matt Damon
Batgirl's Wing Batwing Electrolysis Ben Affleck Matt Damon