I want to give some sage advice. I am older and have come to understand some things via experience. This boyfriend of yours is afraid to be alone. He cheated on his wife with you, he will cheat on you. He has some serious issues with honesty.
You are beyond this.
I made a pact of never being the other woman in a relationship after it happened to me. Walk a mile in his ex wife’s shoes. Don’t start wearing them for the rest of your limited relationship with this guy. Basically, he’s a mess and you don’t need to take on someone else’s issues. We all have our own. You see the future by watching his past.