Sorry this is so long!

For our son's 2nd birthday, my DH and I had decided to do a small family gathering and since DS birthday fell very close to my MIL's birthday, we decided that a joint celebration would be nice. So, my DH sent an email to his family and asked which weekend (choice of 2 weekends) would be better for everyone. Replies from both his older and younger brothers came in, and it was decided that 2/28 for an early dinner (5pm) would work for everyone.

Within this email thread, my FIL replied, "Any thoughts about X & X's birthdays which are in Feb, too?" These are my younger BIL's sons who's birthdays are 3 weeks before my son's birthday and who are significantly older and will be having a separate party with their friends. There was no response to his comment. So, we decided to move forward with dinner on 2/28 at 5pm.

Next thing you know, my older SIL sends out an email with the title "February Birthday celebrations" and says that she will host the celebration (because she has a leftover ham that needs to be consumed before March) and since the 28th is not great for her kids' schedules since it's on a Sunday night, let's move it to another day. Younger SIL chimes in and says the 20th works for her and together they decide on the 20th and completely hijack the celebration.

I'm sort of stunned and speechless because I had invited my family to this gathering since it's initial intent was to celebrate my son's 2nd birthday AND we're not even available on the 20th. So, I write a response back stating that exact thing...the initial intent was to celebrate DS's second birthday and we're not available on the 20th.

There were two replies back with no apologies, just, "Well, I guess we should stick to the original plan for the 28th..." and "Can we have an early dinner on the 28th? We'll have to leave at 7:30."

We WANT them to leave at 7:30. Our kids are in bed by 7:30! What really chaps my hide, though, is that had I done my older SIL, she'd be all up in arms.

Just thinking about this gets me all hot and bothered again...Maybe I'm overreacting, but now, I don't even want to have a get together. Let them have their shin-dig with ham on the 20th and we'll have a nice quiet party with my side of the family on the 28th.

Am I overreacting? Do I just let it go?