Why is it that the last three people who've hit on me have:
-had a girlfriend,
-been married, and
What could I possible be doing thats attracting people already in relationships? Or do boys just hit on anything that may, on occasion, wear a skirt?
-Don't Want to be the "Other Woman"
It's a widely discussed sentiment that men are cowardly and useless. Regarding asking women out, that is. (Ok, it's not just that area, but let's focus on one issue at a time.) They rely on a wingman and then throw out vague, easy-to-recover-from invites to "hang out." They have to be spoon-fed the idea that you're interested and in the end, we all but ask ourselves out! Delightful. Well done, guys.
So how come these guys are so open about their interest in you? It doesn't matter for them! If you say no, well, they just go home to their unsuspecting lady who can inevitably do better. Nothing lost! And if you say yes...SCORE. For them. (Not so much for you, since you're now a homewrecker, and definitely not for the girlfriend or wife. Because they've been fooled by this horrible manchild.)
So you're not doing anything wrong! It is, predictably, the fault of the Y chromosome here.
Such is life.