Is it considered NOT OKAY to have a girl who isn't a stripper at a bachelor party? Shouldn't it be MEN ONLY??

My fiance wants to invite a girl who is a good friend of his to his bachelor party. I think it's an ALL GUY event and the other guys would probably feel awkward, right? I know this girl, she's married to one of his best friends and wants to take part in the festivities--I'm not having any men at MY bachelorette and would never even THINK to ask to go to a guys bachelor party... but now my fiance feels bad b/c she already asked to come along.. should i be irritated?