Last weekend I went out with a group of my girlfriends to celebrate a mutual friend's birthday. When we walked up to the bar, my ex was there with his girlfriend of over a year. Since I see this particular ex of mine as strictly a friend -- no romantic feelings whatsoever -- it didn't faze me to run in to the two of them.

That is, until his girlfriend turned around, gave me the middle finger and called me, well, an effing bee.

She'd voiced her disdain toward me in the past, but this was the first time she'd been so blatant or done it front of my ex. Since I have never done anything that warrants her (somewhat accurate) judgment, my ex just stood there looking like a deer in headlights. So much for thinking he'd jump to my rescue.

I can't fault him for not taking a stand -- I suppose that would open a whole other can of worms in their relationship. But I don't grasp why my ex's new girlfriend won't try to get along with me (or at least ignore me), especially when my ex and I have the same group of friends.

Help me out -- what's your best strategy when it comes to making nice with a past guy's new girl? What should I do if she's nasty like that again?

Kristen Rollins blogs regularly about sex and relationships for Lemondrop.