Siege the castle
A game where one person clinches their butt cheeks while the other tries to penetrate them.
I was trying to siege the castle, but I wasn't making any ground.
sieging the castle
verb: a sexual act done by tucking your erect penis behind your legs (see mangina.) You then get a female to inspect this area and then release your surprise cock, creating a battering ram like motion into the girl's chin and/or eye.
She thought I was just doing a mangina, but she didn't know it was a trap and I was sieging the castle.