KOURTNEY KARDASHIAN furious with baby daddy SCOTT DISICK after he was caught at a New York club at three AM.

The “Keeping Up with the Kardashians” beauty – who just gave birth to the couple’s second child, daughter Penelope, in July – was sound asleep in Los Angeles when a friend called from New York to tell her that Scott was pulling an all-nighter. In town for Fashion Week, the 29-year-old entrepreneur and restaurant owner had assured Kourtney he was “taking it easy and definitely not partying,” a source revealed.

“So when Kourtney got the call, she felt let down and betrayed again.

“When Kourtney finally reached Scott, SHE ripped into him and told him they needed to talk about his party-boy antics – again. At this rate, she feels like maybe her family’s been right all along – Scott will never change.

“And she’s starting to have second thoughts about marrying him.”

Scott has butted heads with the Kardashian clan over his drinking and lack of ambition ever since he and Kourtney, 33, first started dating in 2008.

Recently, he horrified the tightknit family when he left his and Kourtney’s 2-year-old son Mason locked in a car in sweltering 107-de­gree heat while he browsed at a newsstand. Kourtney was understandably outraged.

AND she got steamed again when she found out that Scott and some male friends strolled into the 1OAK nightclub at around 3 a.m. on Sept. 8 for Fashion’s Night Out. An eyewitness said he looked haggard and unshaven.

According to sources, Scott explained to Kourtney that he was just out net­working and making business contacts, but she isn’t buying it.

“Kourtney is getting really tired of hearing the same old excuses from Scott,” the source added. “At this rate, they’ll never get married.”