I don't quite think she comprehends what GUYS night is...

Why did you need to ask permission? I never asked my husband for permission to go out, it was more along the lines of "Did you have anything planned for next weekend? No? Ok, the girls and I are going out for dinner/drinks". He would never have told me I couldn't go, and I would never have told him he couldn't have a "boys night". I'd always have flat out said "it's just the girls, no partners" and he'd have done the same if I'd wanted to go to his night. It's healthy to have friends outside your marriage, and it's not healthy to do every single social activity with your significant other for the rest of your lives.

Either you don’t have the cajones to stand up to her and/or explain what a guys’ night is, or she wouldn’t take no for an answer and tagged along anyway. Either way though, there’s something going on here that you should examine more closely.

Man Card: Revoked!

If you need space, ask for space. Gotta keep those lines of communication going so everyone knows what they want and can expect.