It's one of many reasons I divorced 2 spouses. They both did drugs secretly behind my back, knowing that I did not approve of that lifestyle. They became more controlling, mean, and abusive over time, so I divorced both of them. I could never figure out why they didn't choose someone that had things like drugs in common with them--but maybe it's because now one is homeless and the other one lives with his Mommy, and they are both in their 40's.
I have 3 beautiful children by these 2 idiots, and they are not allowed to have visitation because of drugs, alcohol, and violence. Of course now that I'm older and wiser, I realize that I have co-dependency issues--but I did not know when I married them that they were drug users.