Be passive about it.
Be more assertive.
The solution is simple, push back. Be an starfish to them if they start up, they'll stop messing with you once they get the picture that their stuff isn't going to fly with you.
http://www.youtube.com/watch?v=x7JVLipzwbM&feature=related
I lol'ed.
I need help. There are a few people who I hang out with that are complete richards to me when we are with other people. But when it's just me and that one person, we get along great. What the hell is going on?