See I absolutely agree with people saying husband hiding the drinking is a problem, but also think there might be an issue with OP as much as the husband here.
As in I’m not sure we’re talking about the husband hiding that he’s drinking excessively, I think he’s hiding his drinking because OP thinks it’s only ok to drink at weekends, and she’s fed up of him drinking several times week. Also he’s been forced to hide his drinking.
Bloody hell drinking in the bathroom is not normal, but given that OP says this “ He knows I don’t like him drinking several times a week, he drinks in the bathroom while listening to music, why can’t he just drink a glass of wine at the weekend like normal people” I wonder if he has a choice!
Op there’s nothing unusual about drinking several times a week, even having a glass of wine every night with dinner, in fact that’s probably better for you than just drinking over the weekend. Many European countries drink every single night.
Now if your going to come back to me and say he’s drinking a bottle a night on his own and that’s what you object to yes your husband has a problem if however your screwing him up over a glass or two a few times a week then the problem is more in-house side than his.
But absolutely the worry is he’s hiding the drinking at all.
You either need to relax or seek help. Either of you both of you.