Gents - yes ; Mens - no

When you gotta go, you gotta go so you look around and there they are. Thankfully the public loos loom in to sight. Properly marked to herd great queues of women one way and the short queues for men the other.
So what is it that really gets me going? Ladies and Gents. Yep. That's a description of who goes where. Or Ladies' and Gents' using the apostrophe to indicate who they belong to (well the council or the pub really but you know what I mean. Or Women and Men or Women's and Men's (are you following me?)
BUT THERE IS NO SUCH WORD AS MENS IN THE ENGLISH LANGUAGE - at least not yet.
One man, two men. Plural. Right? So if you want to describe who goes in those toilets then it's MEN.
If you want to say that the toilet belongs to men as a group of users then it's MEN'S in response to asking who they belong to? Answer: Men. So whack in the apostrophe and add the 's'. Yep it's different because the plural is an exception and yes, English is nuts.
SO  maybe they should just stick to putting little pictures of someone in a skirt and someone in trousers and leave it at that. But hang on. I look down and I'm the one wearing the pants.