Can I fight him on this?

Cailey

My ex says the SECOND my son turns two he’s going to turn his seat around. I want to wait until my son is bigger and not go by age (because I actually care about his safety. Unlike my ex who just cares about what’s easy for HIM 😡)

Anyways I’ve told him that my son WILL be remaining rear facing for as long as he can and he keeps saying “not while he’s with me.”

If I have sole legal custody can I fight him on that?