Is it normal for me to get jealous about this?

Wtf is she taking another guy instead of YOU ????

You should definitely meet the guy before he goes off as your girlfriend's invited guest to spend quality time with her during the course of a week.

Why aren't you going?

track the guy down and beat him up or arrange someone to do it.. i'm kidding you have every right to be jealous if the situation was reversed i'm sure she'd be too. tell her what you're feeling but careful how you bring the issue up he she suspects you don't trust her you'll piss her off. guys and girls can be friends but there will be some attraction at some point it's inevitable. just talk to her bro

Maybe he's gay.

It's ok for girls to be friends with other guys, but the fact she's taking him on vacation with her friends instead of you is very suspicious. It could be just that he's a cool friend, but like the other's said - why aren't you going?

The only thing that concerns me about it is that you haven't met him. Do you go to the same college? Why aren't you going with them? Are there other guys going?
My boyfriend has spent a day or two with female friends... but these are women that I have met, and who were friends with him long before I knew him.

Unless the guy is gay, yes, of course you have the right to be jealous. You're the one supposed to be on vacation with her, not some random dude. But maybe she's trying to hook him up with one of her girlfriends... Girls are complicated. You should just ask her what's up with this guy.

Ya, I would not be cool with my girl taking another guy on vacation with her. I would be hella jealous!

That's messed up. How would she feel if you took some other girl on vacation with you?

That is weird. I'd be concerned.

Heck yea, its normal to be jelous!! personaly, I would hire a spy !!

Are you jealous of him or her? O.o
Tell her you don't feel comfortable and get to know him before!