Our sitch is such: I have one son, 7, and two sd's, 7 and 4. Their birthdays all fall in the summer, sd7's was the last day of school, son7's falls on Father's Day, and sd4's is on July 6th.

Myself, my FH, his ex-wife, and her FH are all in voluntary group therapy, to help deal with the communication issues that their divorce left them with.

The therapist suggested that we keep an online, mutually accessible calendar for the girls' events. School, sports, social, etc. So, we do.

Now, since all the kids' birthdays fall in the summer, we wanted to have a combined party. Months ago, we selected a date that fell during our every other week custody period, June 26th. We put it on the calendar. It was verbally acknowledged that period of time was set aside for our party. Since we didn't have custody of the girls during the last week of school, I sent our party invitations to school on the Friday of our week of custody. Family members and non-school friends all got e-vites.

It was also established that BM wanted to have a party too, for the girls. She contacted me to help her with decorations, since I did set-design in school, and she wanted to do some massive party decor. I agreed to help, and asked when the party would be. No response for over a month. Last week when we dropped the girls off with their step-dad, he told us he thought the party would be on June 12th, which is next weekend. So, today I contacted BM to ask if the 12th was still the date, and if she still needed help with decorations.

The response I got back was surprising:

"No need at this point. Cancelling[sic] the party since you already invited all their friends to yours."

...

Since she had mentioned the possibility of combining the two parties at her house earlier in the year, I asked if she wanted to combine at the park where we were having our party instead of having two separate events?

"Hell no."

So, I want some feedback. Am I somehow the a**hole for planning this party? FH asked that I take care of it, since party planning isn't his strong suit. If she didn't send out invites while the kids were still in school (since the school won't provide addresses or emails for other students, for privacy reasons), is that somehow my fault? She had tentatively scheduled her party before mine, wouldn't that provide the girls' friends a chance to come to one if they couldn't come to the other? Is it fair to the kids to miss out on a party with their BM's side of the family because she's mad I invited their classes?

*sigh* I'm about wrung out. I don't know how I became the bad guy here. I want all my kids to have good birthdays, and I know how hard it is to coordinate a summer birthday party with friends you only see during the school year. Hell, my birthday's during the summer, so I had to go through the same thing as a kid. Didn't get your invites out during the school year? Unless you could track down all your classmates' addresses outside of school, it's rough getting invites to them.

Thoughts?

(X-posted from the Blended family forum)