Emily Post Where Are You

What is the proper etiquette, the socially-correct response, for an ex-of-sorts's announcement that he and his girlfriend have decided he would be happier as a woman, so they're going to start him on hormones, and chop off his willie when the time comes?

This is someone I still care about alot, so I feel like I should be happy for him, even though watching her physically assault him for speaking with his normal voice, because it's too masculine for her, makes me uncomfortable.

I've never been good at expressing my feelings, especially where guys I like are concerned. But this is a silence that's greater than all the rest, the confusion in my head, and in my heart.