Girl's Behavior

Why do girls in relationships do this?

So I noticed I get hit on by girls who have boyfriends. I don’t even get the point of flirting when I’m not gonna go after cheaters. Like what’s the point? Not only that, but I just want to mind my own business without the potential of getting into a fight because the boyfriend is jealous. Even at the gym, some dude yanked his girlfriend’s arm because she was staring at me more than he felt comfortable with. I just want to be left alone. Why don’t single girls act this way with me? It’s always girls in relationships that try the hardest with me. Stuff like this makes me not even want to be in a relationship.
Why do girls in relationships do this?
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