I found out about the coke followed by the affair shortly after from what I got told she is a user also, I’m not sure how fare it went as she wouldn’t speak to me and he played it down, he couldn’t tell me why he did the coke or played away.
I would saying he was using at least three days of the week, and like your husband it’s when we are in bed and he will sit up most of the night (clamming to be watching a film).
He has always been a moody old sod but I do notice the changes in him. Last time I caught him using the coke I found it in his wallet but haven’t come across anything as of yet.