Awhle back, I read a theory where grandpa dunham was hitting ho’s. Barry was Gramps love child and he made Stanley become the mom.
It made as much sense as anything else although it would not explain the BC coverup.
But if grandpa was hitting hos why would he care if some ho got pregnant?
They didn't have DNA testing back then. The last thing grandpa would do would be to take such a baby into the family and raise it. It would be the ho's problem, not his.