Kourtney left taking care of the kids.

New Mom Kourtney Kardashian is stuck in Los Angeles with 2-month-old daughter Penelope and 2-year-old son Mason while her partner Scott Disick was in NYC, where he was spotted 'partying up a storm' during Fashion Week, according to In Touch.

"He thought nothing of leaving Kourtney and the kids behind and flying to New York. It’s sad but typical," an insider tells In Touch.

A report claims:

Kourtney was dealing with a crying infant and a son in his terrible twos, Scott arrived in Manhattan on Sept. 5 looking for a good time.

“He lied to everyone and said he was just coming to NYC to host a Fashion Week event, but that was far from the truth,” an insider blabbed.

“He was hanging out with his guy friends and hit up Soho House. He tried to keep his whereabouts off the radar so he wouldn’t be photographed or piss off Kourtney.”

At one restaurant a staffer complained that he later sent in three tables of girls and called to make sure that their dinner was free, the report claims.

“They’re just random girls who he’s met through his various trips to NYC; it happens all the time,” another insider tells In Touch.

“Sometimes he calls in from LA to comp women’s meals," the chatty source claimed.

Should Kourtney stay with Scott?

(Image: WENN)