How To Congratulate A Friend For Engagement I'm Not The Jealous Type, But I Am Wary Of A Friend Of My Fiances?

I'm not the jealous type, but I am wary of a friend of my fiances? - how to congratulate a friend for engagement

I know the title sounds like a contradiction, but there are circumstances.
My friend is a close friend of the people I with the property until we have announced our commitment (which meets for four or five years). Another mutual friend had warned me of what I felt from my friend, but he has never tried anything from the requirement, even if we grow around each other, there are plenty of tension. The other night at 3 clock in the morning called my wife, who responded with speaker, he was drunk and emotional, and, as he went, and she thinks love will be together the next day he played as a joke, but I am convinced it is something else. My friend did not respond to their calls, but I can say that bothers you, it's probably one of its closure ist friends and I do not think she saw that one coming. We've talked about it, but you do not know what to do. He has since apologized to me and we congratulate him and said she was sorry if he caused problems and realize its time to move. How do I deal with this situation.