When performing oral sex on man who is sitting on a wooden chair, the partner will suddenly take the man's nuts and slam them as hard as possible against the chair in a attempt to force a painful ejaculation . This was popularised in Philadelphia through a social media challenge.
My girlfriend was giving me some good head when suddenly she threw me a Philadelphia Slammer, it was so painful that I cried like a baby.
by Ghost witchet August 12, 2019