when youre partner(another boy or girl, can be gay or strait) falls asleep, but you can have sexual intercourse with them. Only works if the one doing action is a boy.
Last night I was super horny, so before Linda fell asleep she said I could sleep assault.
by statonstaton January 19, 2012
2 more definitions
when you are asleep and someone you have never been intimate with before wakes you up and starts kissing you and generally leads to engaging in sexual activites
"dude i was falling asleep and then amy came into my room and sleep assaulted me, it was totally hot"
by seanbasil89 February 24, 2010
A sexual fetish involving the fantasy of performing sexual acts on or with a person while they are asleep. The reverse fantasy is of having someone perform sexual acts on or with you while you are asleep.
I would love it if my husband would sleep assault me.
by abacadabra77 April 13, 2015