You seem worried too much about what other people think.
I used to get offered alcohol all the time at parties, sometimes still do. "No thanks" was my main response. People who knew me as a heavy drinker would ask why or sometimes tease me but I'd laugh it off. What else could I do?
I'm a lot more quiet at gatherings, a bit of a loner. People probably think I'm bored or stuck up. lol Compare that to how I was when drinking: Outgoing and friendly, progressed to annoying, progressed to drunken a**hole...
Bottom line: my sobriety comes first. I'm selfish that way. Who cares what other people think? I'm a much better man now than I was 5 1/2 years ago!
If I were you, I'd skip that party. Just not worth the risk.