Is this a weird request from my best friend who happens to be a girl, for her Bachelor Party?

We are both 22 I've known her for 5 Years now we are best friends I am a guy and yes very straight lol She is getting married in a month bummer because I was in love with her :'( but I'm happy for her. Yet, she called me the other night and said she had one final request and that she wants to spend a week in Las Vegas just with me in a Villa. I was like "Yes?" but I'm thinking isn't that a little in appropriate that me and her will be alone in Vegas in a Villa for a week? I mean of course I want to go! but should I go? and why does she only want to go with me?