Would you be angry ?

I understand your partner is providing financially, but it’s not like you don’t work all day? Stay at home mum is a full time job and should finally be acknowledged as such. I’d sit down with him and open up about how you feel. Perhaps he could skip the gym a couple times a week to give you a break? I’d package it as a positive for him too as in he gets some 1:1 quality time with baby 🫶

you’re not ungrateful for wanting a break from taking care of your baby. you can probably talk to him about alternating days where he spends the evening with the baby while you rest or do something else. If he goes to the gym everyday to de-stress and stay fit maybe he can go on walks/runs with your baby in the stroller whenever it’s his cardio day instead of going on the treadmill, and you can take that time for yourself to de-stress in your own way.

I think you should take turns sleeping in since he doesn’t start work til 10 and go to the gym every other day so you get an evening break

Yeah as others have said you both need equal time for yourselves. He can’t expect to go gym every day at the expense of you never having your time. For every night he gets to do his own thing, you get a night as well 🤷🏼‍♀️