A.M.
Who are these other children and why are they over every night? Is he helping and being a co-parent? It sounds like you guys need a talk about what responsibility each has and divide up the work. One of my friends who found she was arguing with her husband all the time about housework and didn't really want to do that much arguing put up a list of the things to do, they now put their initials and date when each does a chore, when it becomes apparent that there are a lot more initials of one rather than the other, then the other knows to get off their tush and do some chores.
Having a sleep over once in a while is fine but it doesn't have to be that often.