FWMB is short for 'friends with minor benefits.' Two individuals who are casual friends, and not dating or engaged to each other, but who occasionally engage in noncoital sexual activity, such as oral or mutual masturbation.
Jenny enjoyed a FWMB relationship with Peter, and his peter; but because they did not go 'all the way,' she felt that she was a good, pure Christian girl.
by Big Sky Heidi December 11, 2009
by Alique Compton March 21, 2017