As nice and mature as it sounds to stay friends with exes, we've never been very good at it. There's just something weird (and forced and unnecessary) about maintaining a relationship with someone you're trying to move on from.

Turns out, science is on our side.

According to a study from Oakland University, people with "dark personality types" stay friends with their exes for "practical" reasons, which is as devious as it sounds. "Practical" reasons can be anything from sex to wanting to be able to use or control you.

So, if your ex wants to stay friends with you, there's a good chance he's either a narcissist, a psychopath or both. (Shudder.)

We knew there was a reason we've been ignoring gross David's gross Facebook messages.

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