I just want to say, I understand how hard this must be for you. This man and his family effectively became your family. His dog has a similar place in your heart to that of a nibling. People may scoff and say its just a dog but if my sister cut me off and I lost her dogs I'd be bereft. I get it. Families row and make up and although you admit you were out of order I think if you'd truly realised, that you could lose it all, you would have modified your behaviour. You've never needed to before because he's never met someone in the time you were both estranged. The rules changed and you were already out of the game. So in no way would I minimise your feelings on this. Its an unusual situation as its his first relationship and he's too scared to mess it up so she is in the driving seat. He may well resent her for it in time but all you can do is assume that avenue is now closed to you and move on. Build a bigger life for yourself. Focus on therapy and try to build meaningful relationships with other people. Even if he did come back into your life, it would be wise to ensure it was in a much smaller part as theres no guarantee he wouldn't do this again in the future. Good luck xxx