10. How much currency to get and where to get it.
9. Making it to the airport on time. Personal account: The only time I've ever missed a flight was while traveling with a boyfriend. I never hated anybody so much as I hated him for about 15 minutes.
8. Money again! But this time, in the context of spending too much of it. Who doesn't?
7. Your ladylike habit of taking three hours to get ready for dinner.
6. Packing: too much for you, not enough for him. No, you didn't need twelve pairs of shoes for seven days, but could he at least have brought enough clean underwear to last?
5. Reading maps. Getting lost, especially abroad, brings out the worst in everyone. At least with GPS's and smart phones, you don't also have to fight about how to re-fold the paper map anymore.
4. Drinking too much. Yes, honey, we're on vacation, but you're still embarrassing me!
3. When and where to have a meal.
2. Activities: It's apparently a common theme that women want to lounge in the sun, where as men want to get up and go.

And the number one reason is....

1. Men checking out other women. Rude! Also, aren't sunglasses supposed to help hide this problem?

From Glamour.com