Your WS sounds a lot like mine in some ways. And he had been a lifelong cheater, he especially liked married women. He felt NO guilt. He said that "as long as no one finds out I'm not doing anything wrong." This may be your WS thought process too. He enjoys what he is doing. He will not want to stop. He will do/say whatever he has to to keep it going.
You may never know the whole truth. I still get TT three years later. But what concerns me is that it doesn't seem that your WS has stopped. He doesn't sound remorseful, isn't recognizing dangerous behavior isn't being honest.
I would encourage you to take a deep breath, a step back and 180. Is this the kind of person you want to spend the rest of your life with? Is he living up to YOUR standards? Are you getting your needs met?