Knight Bonding
A sleepover created just so a group of male friends can jerk off with each other while thinking about the sleepover host's sister. It is common for the host of a Knight Bond to provide family pictures of the sister for the masturbation session.
Guy: Thanks man, that Knight Bonding last night was amazing! Your sister is so fucking hot.
Host: No problem, thanks for bringing the lube!
Host: No problem, thanks for bringing the lube!