The latest rumors surrounding Kourtney Kardashian and Scott Disick suggest that the former previously cheated on the latter. After Kourtney's alleged romance with Justin Bieber surfaced, the former partygoer is reportedly thinking if he's the father of their youngest son, Reign. Disick now demands a paternity test to prove it to get even with Kardashian.

As reported by Celeb Dirty Laundry (CDL), Lord Disick was disappointed when he discovered Kourtney's alleged relationship with the "Sorry" singer. The father of three also reportedly now suspects if Kourtney was really faithful to him when they were still together.

This is not the first time that Kourtney's fidelity was questioned as earlier rumors also suggested that Mason is not Scott's son. A model, Michael Girgenti, who had a fling with the 36-year-old earlier argued that he might be the father of Mason.

"Now that Scott knows how easily Kourtney hooked up with at least one other man since dumping him, the self-proclaimed Lord is starting to think there might be a real chance that Kourtney stepped out and Reign isn't his son," an insider revealed.

In Septemeber, Gossip Cop busted OK! Magazine for its false report about Kardashian and Disick. OK! Magazine was the first to report that the 32-year-old was questioning Kourtney if he fathered Reign. It added that the "Keeping Up With The Kardashians" star doesn't really have a clean image off-screen and that their problem was not only to be blamed to Disick.

As Kardashian and Disick's relationship becomes shadier, an eyewitness close to the family revealed that "Scott feels like Kourtney is acting like a child and that his 36-year old former fiance may have been hooking up with Bieber or other young men while they were still together."