I would say go and enjoy yourself. But, to be on the safe side, don't tell any of your family until after the fact. Then if they say something to you - play the innocent card.....since you've been inactive just say "hu? I knew you couldn't go to church services but I didn't realize you couldn't go into a church for a wedding" - you won't get DF'd for that. Especially since the WT (as quoted above) does not support a DF'ing for it.
Bebu - I can't speak for all Jewish people, but I have a close friend who is like a second father to me and he is Jewish. He would not go to a wedding held in a church.