Is monogamy a made-up fairy tale or what?

I may or may not have been briefly involved with a person who is "taken" but my friends tell me not to worry about it as it isn't "my fault" and that it's "on her."

What would a person say to the significant other who was cheated on?

Now that I think of it, ot happened to me a lomg time ago. I was just hurt. I didn't want to hurt the guy who she cheated with. I was just disappointed and ended the relationship.

So regardless of whether or not I knew she was taken at the time - what am I supposed to say if I'm approached by some angry dude? I doubt he would want to talk much am I gonna get jumped? Like wtf.

How do ppl even trust ppl enough to marry each other these days wtf. This is frustrating and I can hardly get a date yet the last two chicks I got with have been married. ZERO attention from single ladies. One particularly stuck up bitch responded to me, "ughh not with you" and I didn't let it phase me but it's bothering me. Why are single women completely uniterested, yet I had these random encounters that were explicitely one time deals? I hate myself right now.