She expects you to be mean and impolite to the OM. Have you considered being polite to him if he's there? That would throw her for a loop - especially if he's the one raising a fuss.
Her internal dialogue: Well, maynard sure is being nice and civil to OM, why can't he behave himself civilly?
That's a lesson I learned too late from a friend who was constantly reminding me to behave kindly to OW, even though she was making constant phone calls to my house insulting me through my answering machine. Don't even know where she got the number. And she's gone, baby, gone now!
Good luck in however you choose to handle this situation. And HAPPY BIRTHDAY. You have every right to feel good - you're doing the right thing, discovering your patience. It's hard to keep going through this process when the WAS's anger cuts you to the core, and she has absolutely tried with you. Sometimes they don't realize how petty they're being until they've had time to reflect - they're just acting on instinct... and instinct has a way of always wanting revenge, even for imaginary wrongs.
Me: 26 Ex: 27 Son: 5
Divorced: 3/2010 Each day is another opportunity to do it right.