I need answers

I like having a black and white still of answers and right now I have a question that leaves me with an answer in the gray zone and I need opinions:

So my fiancé and I have been together 3 years and I have seen multiple times that he tends to hold very open and personal conversations with other females while/after he’s been drinking. Well the things he says he doesn’t exactly say to me and I’m considering this to be a form of or boarding on having an emotional affair. And he doesn’t know I see all these messages because most the tome I get to them when he is passed out. But the other night he woke me up when he got home from drinking and then when back down to the living room so I pulled his old phone out that I have hidden and opened his FB messenger app and saw the conversations as they were happening. Some of the things I saw were innocent but one conversation he basically told a girl (who I believe is married) that he wants to stick it to her and that he had feelings for her before, I’m not sure how long ago this was.

Is this considering an emotional affair/cheating? Or would you just flat out call this cheating?

Only posting anonymously because I don’t want anyone who knows us to know this is me.