SO works overnight

My SO works overnight (leaves the house at 4:30pm is home by 5:30-6am) then sleeps from the time he gets home till 3:45-4 gets ready and leaves. Do you think it’s fair that I have to do everything for the baby? (I work 6-2 every day and the baby comes to work with me) He doesn’t even offer to feed him if I’m feeding him when he comes in from work (on the weekends) just straight to sleep.