Last month I was mildly flirting with a cute guy at a party, which is a rare occurrence for me. My friends are overly supportive of me finding Mr. Right, so the night became a play-by-play of them pointing out everything this guy did to demonstrate his attraction to me. There was just one problem: I didn’t know if he had a girlfriend. He was there alone, but he never mentioned a significant other. Someone said it didn’t matter if he had a girlfriend because “maybe she’s a bitch and you’re way better than her.” Her statement stopped me in my tracks.

Why do women automatically assume that if a guy has a girlfriend it’s ok to flirt, make out, or even sleep with him as long as the girlfriend is presumably a bitch? The mythical, evil girlfriend who holds the poor, innocent man hostage in a relationship where he’s under-appreciated and emasculated. Like Taylor Swift does in her song “You Belong With Me,” women picture themselves as the nerdy girl who can rescue the quarterback from his hellish relationship with the cheerleader. Why does the nerd girl excuse his flirtatious behavior when she knows he’s with another woman? Better yet, where in the story does the guy take responsibility for ending his shitty relationship before pursuing another one?

This seemingly-accepted behavior stings because I’ve been cheated on—a lot. One boyfriend cheated on me with a co-worker of ours. She actually divorced her husband to pursue him while we were still together, completely disrespecting me as a fellow woman and as a friend. To her, I was the bitch girlfriend and my boyfriend needed rescuing from my supposed tyranny. She cut and dyed her hair like mine, dressed like me, and exploited faults in our relationship to win him over. It worked; he slept with her and I dumped him. They have a kid together now.

My last boyfriend cheated on me twice, and both times the girls knew he had a girlfriend. The first time he was drunk at a party; he had unprotected sex with a girl in a garage after he went in there to help her find her shoes. (Apparently her shoes were in her vagina.) Like the idiot with low self-esteem that I am, I bought his apology about how he’d never do that to me again—because he loved me. We stayed together and tried to work it out.

The second time he cheated on me was after we went on a date. I had homework to do, so he went to his neighbor’s house after dropping me at home. The girl he slept with that night had the audacity to come to his house the next day to tell me that I was “fucked up” for being with him. She said he’d spent the night complaining about problems in our relationship (then they both commiserated about coming from broken homes with dead fathers, which lead to sex—seriously, that was his reasoning).

That second time I understood what the cheerleader in Taylor Swift’s song must have been feeling: her emotionally immature boyfriend was using serious relationship issues to get attention and sympathy from another woman—and she bought into it.

Why are girls are so conditioned to rescue men that they’ll allow them to cheat, hurting a woman they don’t even know? The girls my exes slept with didn’t consider the girlfriend on the other end. I’ve always blamed men for being cheaters and players—I think we’re raised to believe it’s in their DNA—but I wonder how those behaviors would change if women stopped doling out sympathy sex for the poor, tortured boyfriend routine, and insisted he deal with his girlfriend issues instead. What if women stopped going after “taken” men in manipulative ways, and demanded the guy dump the other girl before sleeping with him?

Getting dumped outright would have been so much easier than the drama created by cheating, which included fear for my sexual health.

I don’t see anything wrong with having a little solidarity amongst ourselves as women to refuse the sexual pursuits of men who are in monogamous relationships. Regardless of how much you want to get laid, have a little forethought and compassion for your fellow female. I have no problem if a single girl wants to get laid—this isn’t about slut-shaming—just make sure the guy is single as well.

And even if his girlfriend is a raging bitch, what does it say about a man who stays in a difficult relationship and uses cheating as an excuse to get out of it, or as a way to find consolation during a rough patch? Why would women want to encourage that behavior by rewarding it with sex?

After I discovered the guy at the party did have a girlfriend, I stopped flirting and posited those same questions to my overly-encouraging friend. She admitted that’s not the kind of stand-up, trustworthy guy she would want for me. And while I enjoyed feeling attractive and flirtatious, it wasn’t as fun once I knew there was a girl like me on the other end, waiting for her boyfriend to come home.