Yep. You have the right to be pissed. Thanks for writing in. -The Plunge
Wait, you want more advice? Okay. First off, be careful. If you have a hissy over this, you go from having the moral high ground to sounding like a princess. Besides, most people don't give a damn about ushers. It's a courtesy gig, an honorary appointment, sort of like the pre-Dick Cheney Vice Presidency.
SEE ALSO: Open Bar If Parents Object?
And you're absolutely right to be worried about the precedent. You should have been consulted. Period. Neither you nor the bride--and especially not random aunts or uncles--have the right to make unilateral decisions about who's in and who's out. Besides, Crazy Aunt put you in a very uncomfortable spot; you're forced to either deal with her decision or look like a dick.
Let's focus on the upside:
1) There's no damage done. Unless these cousins are so troll-ugly that they'll scare small children, ruin the wedding photos, and remind your guests of the melting-face Nazi from the end of Raiders of the Lost Ark, it really won't matter. Don't uninvited them.
2) This happened with something small, not big. That's good news. Now you have a heads up that Crazy Aunt--or anyone else in her family--might ambush you with random shit. Nip this in the bud. Have your bride politely communicate to her family that she/you loves their input, treasures their advice, wants to hear all of their ideas...but that ultimately, at the end of the day, the bride and groom make these decisions. To clarify: this is a conversation your fiancée should have with her family, not you.
One more thing. Even thought they're technically "in your wedding party," it's just a technicality, so don't feel pressured to absorb them into your inner-circle. No invites to the bachelor party, no pre-game camaraderie, no series of wedding photos (besides the super-large group photo.) They walk the guests down the aisle, and that's about it.
So, what's the takeaway? A lesson for all grooms: when her family (or your family) railroads you, the time to speak up is NOW. If this goes unchecked, the passive aggressive decision-making will snowball.
Hope that helps-- good luck.
For more wedding complications and reader questions answered, check out http://www.theplunge.com/tag/complications.
Photo Credit: breathtakingandinnapropriate.com