My DS has has horrible luck with women who behave in this way. He got married and raised a daughter for several years, before a divorce when his ex proudly announced the child wasn't even his. Many people had pointed out over the intervening years that she was known for sleeping around, and their child was the spitting image of a guy she was seeing on the side, around the time she got pregnant.
Some months following the break up of a short lived relationship with another woman, my son received a very angry call from her DB, berating my son for not showing up for the birth of their daughter. At the time my son was struggling with health issues and was already in a bad place mentally. He broke down and had a panic attack.
I pointed out that che child wasn't necessarily his, as the timing didn't exactly fit, and that if it was his child, he would eventually see her as the blessing she was. The woman was a fantasist, liar, manipulator and tbh intellectually challenged, constantly tripping up over lies she'd forgotten she told which is why they split, so my son was gutted at the thought of being tied to her for life.
It look a year of her mind games, tall tales, accusations, wildly inappropriate messages and constant emotional manipulation of our son, before we eventually had a genuine DNA test result. She'd lied about sending off several others, after we'd paid her for them. Thankfully it proved she'd lied all along, just like his wife had.
How he had the strength and ability to trust to go on and form a new relationship in time after all that, I'll never know. Thankfully his GF now seems very sensible, caring and a reall decent person.