No one taking care of infant when leaving home lot?

Hi, I have this problem. My teen Sim had a prom and I send him there. When I returned home with him, the infant was in the red in hunger and attention. And both his parents were home and should be able to take care of him, yet they didn't. Should my teen go to the afterparty (and he didn't only because he was to tired), I may lose my toddler. That's just not right! And this is not the first time I noticed that. The day before, when my teen Sim was in school, the same thing happened, despite one parent still being home. He is freelancer writer just for this exact reason: to be able to take care of the infant when all the other Sims are out. This just isn't right. Infants needs to be taken care of. I should not fear leaving the lot and returning to find out the infant (or baby or toddler, I suppose they will be affected too) being taken by the social service.