Hi JK40,
Welcome to the forums. I remember
your intro post. You were very excited. And nervous. I saw you write your post, delete it, ask to delete your account, then rewrite it all again in the matter of a few hours. I'm glad to see you're better and on more solid ground. I love your contributions on other threads.
My advice in this situation of escalating the relationship would be to take it slowly. You said it earlier - escalating would be a consideration for the far future and you're discussing it now because... well... NRE!!!
Enjoy the NRE. Some monogamous couples like myself who married young don't get that chance to feel NRE more than once in our lifetime, so we come here to get our compersion fix by reading stories like yours.

Don't make any rash decisions whilst in NRE. Equivalently, don't make any life-changing decisions whilst in NRE. Most people would not expect a deep commitment so early in the relationship so I wouldn't spook him with one.
Finally, no one has mentioned it so far, but there's the issue of his wife and her security. Can you predict how she will feel if you and her husband were to escalate your relationship? Depending on her views on poly, she may or may not feel threatened by her husband giving a life-commitment to another person. I would agree with those on the forum who say this commitment is more about you and him rather than about her, but I think such a strong commitment could still affect the security she feels for her husband under some circumstances. It's just a thought for future, but for now, I would suggest to just enjoy the NRE.
Good luck!
-Shaya.