She's got this single parent thing down, but she kinda has to...

Kourtney Kardashian stepped out to run errands with son Mason in Calabasas yesterday, and the reality star seemed pretty downcast, which is understandable considering baby daddy Scott Disick is reportedly off the rails again. The mother-of-three had been considering a reconciliation with LD, before he went MIA on a trip to Dubai with Kim and then took off to booze it up at Sundance.

The nightclub-loving bad boy was even spotted with a "very Kendall Jenner-like" brunette at a party hosted by Brody Jenner at TAO during the film festival, so he's clearly not that committed to making his relationship with Kourt work. "[She] hung on his every word. At a couple points in the night, he would briefly put his arm around her waist — but she seemed more into it than he was," a source dished to E! News.

The E! starlet needs The Lord in her life, though, because she basically has no other story line to contribute to Keeping Up with the Kardashians, but she looks like a giant fool for putting up with his bad behavior.