That's cause men can love/ care about multiple women and women cannot do the same. Women always hard focus on one guy at a time, which is why you see them become more disinterested when a guy catches their gaze. It happens everytime. I guarantee, see who a woman currently is "in love" with and you'd know right away that whatever guy she is with is no longer her interest. She can probably return to it later, but she cares only about the emotional now.Sometimes they are genuinely single. Is there a pseudo boyfriend in the background? Probably. Most girls have guys they aren't interested in blowing them up all the time so it's easy for them to find someone to alleviate their boredom whenever they want
The branch swinging is also pretty common as well. I dealt with this not to long ago from a coworker. When she first joined my group she would always talk about her boyfriend; he was some kind of marketing manager at proctor & gamble, a successful guy. As she settled in I would have lunch with her sometimes with other coworkers or by ourselves. I would make her laugh and **** but wasn't actively trying to flirt with her. About two months ago I was in the cafeteria before work and she was there, she came up to me and after some chit chat went Mike I have to tell you something. This is going to sound really weird but I had a dream last night and you were in it, and we were dating. I was like oh really did you tell your boyfriend? He's going to be jealous. And she laughed and went no i'm not going to tell him that. After that I began to think this woman must be catching feelings. Two weeks ago I found out she had broke up with her boyfriend, which did not surprise me. She's on vacation now and has been sending me pictures of where she is at (I didn't put her up to it).
I have a poor opinion of branch swingers. I have a lot of contempt for women who string guys along when they no longer have interest in them and are actively looking to replace them. This is why in my last couple of relationships I have dropped the hammer when things were no longer working out and I didn't care whether she kicked or screamed (which often happened because of my so called "audacity" at dumping). Women are ruthless when they grow cold and feel the guy no longer serves them, treat them like absolute ****, so just the same men should be ruthless. The problem is guys are the one's that actually have the heart, which is why women find it easy to manipulate them.