My parents are divorced and my brother (12m) and I (16f) split time between mom and dad. Our dad remarried after the divorce 9 years ago. His wife has a daughter 10f who lives with them full time now but her dad was around for a little while when they first got together and he left after my dad's wife won custody officially. He doesn't pay anything for his kid and my dad and his wife are the ones covering everything for her.

My dad and his wife haven't been doing so good with money for a couple of years and this year has been the worst yet for them. My mom is doing better than ever though and she's really been stable with money. So my brother and I have a much better life than our stepsister. We get to do extra curricular's and we get nicer stuff in general. This got so much more obvious lately because my brother got to do two field trips and I got to do an international trip with my school last year.

My stepsister had a field trip come up a couple of weeks ago but my dad and his wife couldn't afford to pay for it. They asked my mom to pay and she said no. They asked my brother to ask my mom and he didn't. So dad asked me to ask mom. He told me how much his stepdaughter wanted to go but the school didn't have a fund to cover for families who couldn't afford it. He told me he knows it's not mom's job but they were desperate and just wanted her to have a nice time and she knows my brother and I never miss out and he didn't want her to feel less important.

I didn't ask. My dad got super pissed when the field trip came and neither my brother or I asked mom. And my stepsister didn't get to go which super pissed him off.

AITA?