It's hard to believe she's had three kids!

Kourtney Kardashian opted to show off her rock hard abs in a crop top today in L.A. as she headed to the studio to do some work on the family reality show, and her ex Scott Disick has got to be kicking himself right about now! The eldest K sister gave birth to son Reign back in December, and since then she's lost all the pregnancy weight and then some. This is the best she's ever looked!

There are rumors that the mother-of-three regrets pulling the plug on her nine year relationship and is contemplating taking back her cheating baby daddy, and if that's true, it sounds like The Lord is down for that plan!

"He's trying to get his life together and that includes getting his family back. He's hoping he and Kourtney can put this behind them. He knows it won't be easy. At the very least, he wants to be friends again. He can't believe how quickly this spiraled. He always thought he could keep it together, until he couldn't," a source dished to E! News. "He knows he has to prove himself to Kourtney. He needs to show her he can be an adult. That's all she wants. She knows he likes to party, but she wants an adult who will be there for her and the family every day," the source added.

They say looking good is the best revenge, and we'd say she's nailing it!