AITAH for getting upset about spending $300 on our child’s birthday cake?

The other day, I was doing some bank stuff as we are getting ready to buy a new family car which is fairly expensive. The browser had so many tabs open I had to close some and came across an email in which my wife agreed to spend $300 on a custom cake on our daughter’s upcoming 6th bday.

Here’s some context. We just had the holidays(expensive), did some renos recently and other things so we’ve been spending lots of money.

I had just seen our credit card balance and i was a bit shocked how high it was. We can handle it I’m sure but it really bothers me. I approached her about, we talked about it, it was civil.

When I came across that email I had to look again to see if this was an old email but nope it was the same day, hours after our conversation. I was livid. At first just at the ridiculous idea of spending $300 on a cake when I know there’s going to be lots more to buy for the party. I needed to leave and talk a walk and while thinking i got even angrier because she basically did this behind my back.

Am i overreacting or is this kind of money for a child’s cake that half usually ends up in the garbage absolutely ridiculous? I feel like that should be some of the money that should go towards the car no??

Thanks for reading/listening to me rant and vent