Everybody knew this story - you are alpha male, you have a girlfriend. She wants something out of you - more money, change in behaviour. Or maybe you spend too much time on job and not getting her 'enough attention'. She starts hanging on Tinder, find 'friends' from job or find any other love supplicant. Then she start to spend time with her new friends in order to provoke jealousy. So you would realize 'what kind of asshole you always were' and come back to her crying and begging for coming back or become bat-shit angry. Anything. The purpose of the game is to extract as much emotions as you can. Note that not every situation is like this. Sometimes she is really fucking with this new guy, and think that you're beta and he is alpha.

Note that I can't say about how popular technique in the US, I live in Russia here chick are much more monogamous but accustomed to this kind of behaviour. Basically I heard a lot of myth about russian chicks here on TRP and at RoK. The russian reality - girls are more feminine, many can cook, generally they're better looking and smarter. But they all are fucking manipulation monster. They learn how to manipulate men from the age of 6 I believe. In first grade they're already manipulators.

Also their defensive line about getting 'enough attention' is pretty funny - if you live together for years even if you have 30 minutes you can discuss everything because you know each other so much you wouldn't need to explain most of the details.

Sometimes chicks use this technique when you're not together but they want to hook you. Be careful. But if she has started to date your stupid retarded friend it might be because you're her real target. Or she might want to play with this 2 dumb boys and make you compete with each other for her attention.

You need to understand that the same line of behaviour is used at the office too. Watch Whiplash for example. Example situation - you did extremely great job for the last year, just kicked the shit out of your job. But sociopaths will promote not you but you stupid co-worker. You feel cheated, devastated, a lot of hate towards this guy that bypassed you. But in reality the whole situation was made up in order to make you feel jealous and make you work even more. Because your supervisors perceive you as a slave.