your son can have dinner first. 老爺, your c6 and you can have the second round. I think kids not eat too much, so that you can pick some for him to eat first.
When your son sleeps, your family can have dinner.
Or on alternative days, say Mon-Wed, your son eat first.
Thur, Fri : your son + 老爺 + you eat first, BUT KEEP dishes for your husband.