WTBH-
I am wondering (be patient I don't do this part really well yet), if this is not a great opportunity for you to practice boundaries. I think one could be set without it being about your friend, but about you. That might help with the feeling judgemental also.
I have not had this with alcohol use, but I have a number of good guy friends from college who are married and I don't know their wives as well. I had to ask a couple of them to please their wives know he and I were in regular contact because right now I am super sensitive about stepping over an inappropriate line in terms of affairs. Do I think we were being inappropriate? I don't, but my radar is so sensitive right now (it is with alcohol too) that though it does not always feel rational for me it was what I needed at the time. I suspect it might be similar for you.
I can say this I felt better once I knew what I needed and was able to express it. This is experience is really helping me to "Say what I mean, mean what I say, and not say it mean."