After divorce, it can be tempting to jump back in sack with your ex. But is it ever a good idea?
No, according to Sherry Amatenstein, a clinical social worker and relationship author who stopped by HuffPost Live on Wednesday.
"You see a car coming at you and yet you don't get out of the way. That's exactly what having sex with an ex is like," she said. "Don't do it. Because you're just going to fall back in. It's comfortable, but it's a very bad kind of comfort."
Watch the video above for more of Amatenstein's advice. Then, click through the slides below to test your knowledge of eight celebrity couples who got back together with an ex post-split.