In 2010, in a skit on her Comedy Central show, unfunny comedienne Sarah Silverman told a kid to pee in her mouth, then asked another unfunny comedian, Patton Oswalt, if he’s attracted to children. At first denying he is, Oswalt then made the devil's horns hand sign as he leered at a teen boy passing by.

Oswalt makes devil hand sign

Go here for the skit.