Then he stays home with her.   Then you make his life very uncomfortable for the next week or so , so he never goes this again.  He needs to feel negativity of some kind. over this.   Does she have any friends she could go see?  A babysitter ?     I swear, why can't men put their wives first one day of the year???!!!! Is it too much to ask?   Eyeroll 

"Don't want the skids to feel unwanted/unwelcome." (TM)

"Want skid to feel comfortable about dropping in/staying longer." (TM)

You will need to train H not to spill the beans to SD as most skids are the BM's little spy.   GUBMs love this arrangement and encourage it.

Make sure there are no "bedtime activities" when SD is around and be sure to have him spend oodles of quality time with SD this weekend while you go off to perhaps a botanical garden with your parents.   "Oh, SD would be bored,  dear.  You can stay home with her and get some QUALITY time."

Men don't get it until it impacts then directly.  Talk to H and explain that everything he tells SD WILL get back to the BM and be taken advantage of.   If he doesn't believe it (he won't) just concoct some wild story like you won the lottery and see how fast it gets back to the BM.

Plan another weekend away for your birthday.

As everyone else has suggested, re-schedule.  Then make your DH more worried about disappointing you then a child.  

Seriously, it is one day a year.  But it is the one day that is supposed to be all about you.

Happy birthday! I hope even with SD there this weekend you still end up having a good birthday. And trust me I know your pain!! I've had to endure so many holidays with SD being with us. And I'm not exaggerating when I say I have literally gone through the calendar for the rest of this year or next year and looked at all the weekends and all the holidays to see how many I have to spend with her until she turns 18. Luckily I'm all done having to spend my birthday with her. Last year was the last one and it sucked!! it was right at the beginning of Covid so we couldn't even go out to dinner so we were all stuck here at home eating takeout.

I don't have to spend another New Year's Eve or Valentine's Day with her either. The only thing that sucks is this year and next year we have her for the weekend that is our anniversary.  This year it falls on a Saturday so it's right smack in the middle of our weekend we have her but next year it's on a Sunday and she will be 17 and a senior in high school next year so I'm really hoping DH will do the right thing and she will go home Sunday evening to her mothers so we can have Sunday night to ourselves. But I'm not holding my breath. 

OP-your DH was an idiot for mentioning it-he could have not said anything and she went back to BM as expected.  YOu have two options, go do something alone with your parents to teach him a lesson-after all it IS his visitation time or see if your parents can swap dates if you have to include your husband.

I have to ask though ginger, if the mom has majority custody, why wouldn't you expect to have majority holidays? Not sure what your visitation is.

And I do have another big pet peeve, as step-parents we can certainly learn to work around special dates.  I mean if your b-day anniversary fall on a skid weekend one year, then just celebrate before or after?  Why is that such a big deal? We all know it's more traumatic to swap weekends and create a mess with a HC parent then just adjust our celebration day? 

Also, no reason you can't go out to dinner and celebrate and leave the skid at home...I mean what -do intact homes do? Never celebrate their bday/anniversary?  I mean leave them home alone if age approrpiate or get a sitter.  Why should the BM have to bend to take her home early when HE is responsible for her during HIS time.

I'm sorry but my kids grew up with a father who didn't give a damn and spent the least amount of time possible with them, NEVER took them holidays, his EOW consisted of Mid sat afternoon to early afternoon Sunday.  Took them twice on a week vacation of which he cut early by several days.  Never took them the weeks in summer he was supposed to.  I realize non-custodials can decline their visitation but imo it's a crap parent thing to do, especially when CS is based on them having that time with dad in most cases.  My ex's excuse is he had nobody to watch them while he was at work, even when they were certainly old enough to not need him there (he never remariied).  Instead it fell on me to take up his slack.  My sons have suffered inmensely because of their dads lack of interest and rejection of them.  IMO if you as a step-parent are contributing to their distancing themselves by suggesting to skip their parental time, you're a POS, sorry.  At the minimum you're horribly selfish. The odds of the kids being with dad on your bday are probably 1-2 in an 18 yr period since the day always changes and most dads only have EOW.  Same with anniversaries.  And you can't handle it? 

I'll add the 'the one day it's supposed to be all about you' is just pure American entitled selfish BS.  Just like the wedding day it's 'all about me day' when it's about BOTH of you.  It's one day, it's ALSO one day that can be celebrated at any other time.  I"m pro stepmom 99pct of the time but sometimes the selfishness and pettiness on this board from grown women is just absurd.  

Let him deal with her.  You go with your parents, have a good time. Then next weekend DH will make it up to you.  Weekend away in some nice hotel with a excellent restaurant