There are times when I can be insecure and need validation. But I long ago--probably in my teens or early tweinties--abandoned the tactic of gaining validation by making a man jealous. Now, I just ask for validation. Sometimes that can still be seen as immature, but it's a lot more mature and self-aware than what you're describing in her.

I wouldn't put up with her tactics. And I agree with what has been said by other posters. Just because the sex is good, doesn't mean the relationship is. You can actually find good sex pretty easily without an emotional attachment...not that I'm advising it, by any means.