frenemies

I'm currently catching with "this american life" (it's a popular public radio show in the states), and a frenemies-themed episode piqued my curiosity...

Here's the predicament (as paraphrased from the show):

so you have this friend, but the thought of hanging out with this friend totally stresses you out and you think...are we really friends then? the question is...why don't you cut it off?

And so, I throw this dilemma to you, dear readers...what keeps you from cutting off those "toxic" relationships? and perhaps an additional twist: how does bring a christian affect how you interact with the "frenemies" in your life?