Sounds like something a couple of immature adolescents would do , not adults.
If your marriage is unhappy, would not make sense to make the effort to find out why ?
Sorry you have had this painful experience.
I guess the answer you are looking for, is if this is a JW type behavior. I don't know. Hard to say. He may have some conflicting guilt over the things he has done on impulse maybe, and the behavior you see is a reaction to that.
Probably would be overthinking it.
It is very difficult to be in a relationship with a JW, even one who is "out" because they carry many of the same ways of thinking at behavior.
So I guess I would chalk it up to good luck that you found out about this guy sooner than later.
Dating is tough, and can be painful. Protect your heart dear. Remember this pain, and learn from it, so you don't repeat it. Take care.
Better - and emotionally healthier - fish out there in the sea.