Does anybody know if I am entitled to ask my ex-husband for 1/2 reimbursement of my son's summer Day Camp?

My ex-has powerful attorneys and got the school year shared custody of my 8 year old son because he said his school district was the better school (it's not). My ex also makes over $100k/year and I make $9/hour. I have to pay $250/month child support. I have signed my son up for lots of weekend sport programs and my ex doesn't contribute financially toward them and he doesn't go to them. According to my ex, my son will learn these things in school eventually and doesn't need to join them. (just an fyi, my ex also refuses co-parenting counseling - but he's got all of the power.)

My ex signed my son up for a reading class this summer and wants me to pay for half of the class.

I get my son during the weekdays during the summer, but I still need to pay my mortgage, utilities, taxes and other bills, medical, and child support, so I have to continue to work. There is a day camp I'm putting my son in so I can go to work, but am I entitled to ask my ex for half of the expense of it back? I have a feeling my ex will just say for my son to stay with him over the summer or that it's on my time. My ex won't even let me take my son to dinner during the week during the school year or let my son take home his laptop so he can video chat with me.

I feel so powerless against him. My ex is so greedy when it comes to money. He stole and lied and beat me in equitable too. I don't understand why except that it's keeping him on top and me down. Sorry, needed to vent that too.