What I have always suggested is that people in very early recovery (which I would put at around 90 days) avoid drinking occasions, at least when that is the main event (e.g., cocktail party). After that, the advice I always give is to go with a plan--make sure you have your own car in case you feel you want to leave, maybe bring phone numbers of a couple of sober friends in case you want a little moral support.
There's a lot of alcohol around--an alcoholic can't hide from it forever, nor should he. If you want to have the party, have it. Tell your friend there will be alcohol and that you will understand if he'd rather not come, but that he is invited and you will be sure to have food and nonalcoholic drinks available too (plenty of soda, bottled water, iced tea, etc.). Let him decide.
It's very frustrating to alcoholics to have people worrying about them all the time. It's good and kind to be considerate, but don't go crazy trying to avoid exposing him to booze all the time. He will deal with it, or not, but it isn't your responsibility.
You ARE being very exceptionally considerate, though, not to drink around him, yourself. I think that's really nice and supportive.