Should I forget married men?

It seems that all the men I've met on Craig's List are 80% married straight men. The others are gay men cheating on their partners. I thougt Men seeking Men meant gay single men only apply. I guess I was wrong. Then when they send you their pics, it's only of their front or backside with no face.(in case the wife should catch me). Of course I have met some nice guys that are single ( 1 out of 100) but then they just want the one night stand. Should maybe I put out my own ad and ask for what I'm seeking?