Never do that. As in ever. I'm serious. My dad has done business with FAMILY, not even friends, and they cheated the shit out him that we were to our necks in debt, and we haven't seen a cent from them since. And that was family. But friends too, and it's one thing he taught me: keep friends/family and business as far away as possible from each other. They expect favours, take things for granted because you're family of course.
i think family is worse because of what you said and because of existing dynamics that usually affect the business part too. with friends it might be different, but it always depends on how friends are