How often does your significant other watch your child alone?

Our son is a year and a half, and he has watched him one time when i got my hair done (at like 2 months old), and then the other day, he played with him outside for an hour. Other than that, he really hasn't been alone with him. Am I the only one that thinks it's sad? He's home at night with us, but works 5am-5pm, and then works out and gets home at 6:30, eats dinner showers, plays with us a little, and then we go to bed around 9. He never changes diapers, gives baths, or makes him dinner. What do you think?