Just go and deal with it. Go nuts on whatever catered food he has to make it worth your while, and hang out with your actual work friends. If possible, arrange it so you (and your wife) don’t have to drive so you can drink a lot.
Don’t go. Why put yourself in a horrible situation that will last hours? Make up some excuse and tell him you cannot go, that you already have plans. When you see him next at work, give him a little present and card.
Why not go? Hang out with your wife and co-workers you like. I’ve been to plenty of weddings of people I really like and barely saw them at all the whole time, and we were trying to see one another. You probably won’t have to deal with him for more than five minutes, if that.
Avoid the bachelor party, but a wedding has zero to do with actually interacting with the couple. They’re too busy with ritual to notice you (or anyone else). If he invited you to be in the actual wedding party, that would be a whole different story.
Hang out with your friends. Do some dancing. Have fun.
The wedding. I’m not a fan of attending them. If DrDel doesn’t mind going to weddings though, then go. If he/she doesn’t like them, then don’t go. I don’t think it will make a whole lot of difference either way. People skip these things all the time.
Of course. Most of us have power in the workplace. If the weasel were his superior, then by all means he should go. If he’s just a slimy peer, then they have roughly equal power, and setting up the boundaries of the relationship early is probably healthier than “sucking it up”, to use the phrase of an earlier poster.