|1.||Mandatory sex parties|
Sex parties in which attendance is mandatory. Most frequently seen as part of a sex course or among couples who practice both swinging and S&M.
"Sorry Kelly, I can't make any prayer meetings this week. I have some mandatory sex parties to attend."
|2.||mandatory sex parties|
A party that is disguised as a typical type of party, but really requires you to have sex throughout the night; Obligated sex with multiple people; Raping is involved. The Amazing Allie from Hyperboleandahalf.com coined this phrase.
Guy 1: Jill invited me to her Halloween Party. You goin?
Guy 2: Nah, the only type of party she has are "mandatory sex parties"