I had a girlfriend who ghosted me at the beginning. Just totally ghosted, quit replying to me, would be super evasive, etc. This was before we were intimate. She continually tried to elude me.
Once my penis was in her, it was like a switch flipped, and she became the most wildly devoted girlfriend. On my arm incessantly, super affectionate, PDA, public makeouts, rubbing my cock in public (led to a few awkward situations), but also just a fun girl to be around. She would be begging to spend as much time with me as possible and continually looking for ways to wrap us up more together, which I did not mind because she was super hot, super fun, and a joy to be around... but I was also a young pickup practitioner and couldn't give her as much time as she wanted and still improve with women. I honestly felt pretty bad not being able to give her as much time as she wanted. Nevertheless, relationship went great for two years until I started drinking too much and hitting on girls in front of her and just generally doing a lot of things to her she did not deserve (because she was awesome).
Her personality (of generally ghosting people, judging them, thinking other people were not on her level) meant that when she accepted me as her man, and as a man she fully submitted to, I was basically the only person in her life she submitted to that way. From what I gathered from her, her prior relationships with other boyfriends were similar -- this was just how she did relationships. Cold with people she was not committed to. Totally wrapped up in people she was.
IME, the majority of men respond to this behavior from women by getting butthurt. It means that these girls, who can make super good girlfriends, tend to drive off most guys, who take it personal when she does this to them.
If you don't, you can enjoy what these girls have to offer.
If you do... well, someone else will. Like me ;D