My grandmothers family rule
She almost left my grandfather after they just got married because of drinking, so he decided he would quit because she was a real keeper xD Then both my dad and his older brother took up drinking right after they got married, and she put an end to it very quickly. In fact she went and hunted my uncle down in a bar and dragged his butt back home to wife.
So basically it just something that has stuck among us grandkids, we don't want grandma to come find us.