Do I have a right to be mad at my in laws for ditching my kids birthday party?

My kid’s joint birthday is coming up and my in laws have decided not to come because of sports. I feel kind of pissed off that they are choosing sports over my kid’s party. We have dutifully gone to every birthday they invite us to for their kids and my daughter is confused why her cousins won’t be at her party. I don’t think I’d ever choose a sport event over my nieces. Their one kid is in elementary school and it is a basketball game…it isn’t like she is in some very important game. Her father coaches and is attending a tournament but it isn’t like there are no assistant coaches…am I out of line feeling sort of pissed about it? This isn’t the first time even this year they’ve flaked on an event with us. My husband is mad but keeping the peace by pretending not to be. I have more difficulty pretending…but maybe other people would choose a sport over their niece or nephews birthday party. Note…my kids are their only cousins…so it ain’t like they have to make this choice all the time. I specifically did both kids bdays on one day because their birthdays are close and didn’t want my in laws to have to drive to us multiple times…I just think it is shitty of them but I’ve found sometimes I’m out of line with my emotions so I’m genuinely trying to see if this is one of those times.

I’m sorry, you are in the wrong here. They made commitments to their teams and that is a priority. While I completely understand your frustration, you need to put things in perspective. If it’s really important to you and your husband for them to be there, then you need to consult with them first on their availability. The sports schedule was set months ago.