Drinking while watching kids

Is it acceptable to drink alcohol while taking care of your children? Where would you draw the line between being responsible and not responsible? Do you wait until your child goes to sleep? Is it acceptable during the day and to be drunk by 5 pm? Just trying to figure out what’s common practice among most people. I’m dealing with a SO that drinks while I’m at work and while he’s watching our children. Frankly I’m getting tired of it since he can’t always control how much is consumed at any given time. But let’s just say it’s not ‘drinking responsibly’.