How would you tactfully handle this party situation?

[Chimera]

Dear Friends,

Of course you’re all invited. However, please be aware that this is MY PARTY. The last thing I want to see is any displays of pettiness, animosity, sniping or outright conflict. If you can’t behave yourself, I don’t want you there. I’m not making any accusations here, or even assuming that any of you will be rude enough to be un-civil at someone elses party. I’m just giving you a heads-up that, should anything bad happen, I WILL take it personally and it will strongly affect my relations with whoever is responsible for disrupting my party.
Honestly, I wouldn’t put this in writing, I would say it directly to both people, where the concilliatory tone of my voice could convey that I’m more worried about any issues making things uncomfortable for me and my other guests. But also clear that I’m not about to put up with one or both parties coming in with guns loaded looking for confrontation on MY turf.

[Gestalt]

I agree that you should extend the invitation to the dude’s ex, but also let the girl know so that she has the opportunity to not attend. If I were in her situation, esp if she still has feelings for this guy, I would not want to attend.

[TriPolar]

@Stranger_On_A_Train

Invite all persons of interest to the party. However, for the persons in question, give them another address, one that is at a remote farmhouse on a long, deserted lane. Arrange to have their cars disabled once they arrive. Place cameras in and around the farm house, and then find the scariest bunch of aspiring actors you can find to dress up as mutant zombie motorcyclists to terrorize them. Edit the resulting footage, plus talking head commentary from all of the mutual friends, into some kind of coherent story, and ship it off to FOX. Voila, you’ve just invented a new subgenre of reality t.v.; the ambush-horror show. Profit will ensue.

Stranger

Best suggestion!

[Cat_Whisperer]

@khere

purplehorseshoe, you ask: I don’t want to get into a lengthy discussion about how each of these people have acted, because it’s not really my business and, like you said, it’s better to avoid getting into somebody else’s drama.

If you want to know, the reason why he’s decided not to talk to the ex at the moment is because he found out that she lied to him when he asked her if she’d slept with person X. The sleeping with person X, and the discussion about it, happened after these two had broken up and were back being friends. I don’t think that it’s cool for him to think that he has the right to know what my friend was doing with her private life when they weren’t even together, and for him to suddenly shun her (they were civil and friendly for a time after breaking up) because she “lied to his face” about his unreasonable question. <snip>

Were they on a break?

@MeanOldLady

This is the least complicated thing in the universe. Let him bring his girlfriend.

Seconded. I don’t even have the energy to try to follow all the people getting in each other’s business in this story; he has a new girlfriend, you bring your girlfriend to parties, end of story.

See, this is one of the reasons I’m never friends with exes. I like exes to be just that - EX. You were in my life, now you’re not - simple.

[Hilarity_N.Suze]

Invite everybody, have plenty of booze, hide everything breakable, have plenty of lawn chairs.