A term used to describe a male/female relationship that is entirely non intimate, usually because they enjoy anothers company but have no physical attraction to one another, they are involved in other romantic relationships or, one finds the other attractive and the other is just being polite. A main bled can expect the negative aspects of a romantic relationship, i.e having to go shopping, emotional baggage or attending sporting events, without the sexual gratification. Main Bleds are the opposite of Friends With Benefits.
Dude 1 - Hey, you and Sarah are pretty close, are you friends with benefits?
Dude 2- Nah, we're just Main Bleds
Dude 1- Oh, sorry to hear it
Dude - Hey, fancy going for a drink later?
Chick - Erm, you're not really my type, we could be main bleds?
Dude - I'll pass.