Television personality Scott Disick arrives at the opening of the Kardashian Khaos store at the Mirage Hotel and Casino in Las Vegas, Nevada December 15, 2011. Photo: REUTERS/Steve Marcus/Las Vegas Sun

London - Kourtney Kardashian's relationship with partner Scott Disick is reportedly in crisis.

The father of her child is said to be "on a downward spiral" and "more of a mess than I've ever seen him," according to an insider.

The source claims her sister Khloe Kardashian was the one who "stepped in" and told Kourtney that Scott is back to partying with alcohol.

Despite recently welcoming their second child, a girl named Penelope Scotland, the relationship between the two remains "the worst they've ever been," according to website Radar Online.

The insider said: "Scott is never alone with Penelope because he is so irresponsible." Kourtney is allegedly at the point where she encourages him to leave the house so she doesn't have to deal with him.

The source continued: "Kourtney doesn't even like for him to hold [the baby] because she's afraid he'll drop her."

One source says Scott's taken up the nightlife because he's bored.

They added: "He's a 29-year-old dad with no real job and nothing to do. So he's partying again and drinking heavily."

In the meantime, the reality TV family is "rallying around Kourtney, [as] Scott isn't being a good role model or dad.

"Their mother and manager Kris Jenner is furious that Scott's out in public acting like a drunk.

An insider said. "She'd rather kick him out and be done with him until he grows up.

"The animosity behind them is really bad." - Bang Showbiz