Slut buddy
n: A slut buddy is a close friend that a you probably would not have sex but are, however, comfortable enough to be naked and have sex in front of them. Because you are both sluts it is something that occurs often.
plural, slut buddies
plural, slut buddies
I had sex with this trick but hesitated at first because his roommate was home. Luckily for his roomie was his good slut buddy.