Why do orphans love to play family?
Because it's the closest they will be to being normal.
Listen up, numbskull! The joke is about orphans, who, because they don't have a family, like to play "family." You know, like pretending to be a mom or dad. And it's the closest they'll get to feeling normal 'cause they ain't got no parents. You probably still live with your parents. Pathetic.