We’ve all been there. You’re on vacation — or on your way to a vacation — and you’re in a great mood. Everything’s going your way: you made it to the airport/train station on time, you got the seat you wanted, you have no work for at least a week, you’re super psyched to get your tan on. 

And then … the ultimate buzzkill sits down next to you and harshes your mellow. Well, we’re not gonna take it anymore. We here at Yahoo Travel have identified the worst types of fellow travelers to avoid at all costs — and are giving you a cheat sheet on what to do if you can’t get away.