kimkregsplitup.jpgReggie Bush ultimately dumped Kim Kardashian because of her 2007 sex tape with then-boyfriend Ray J, a source close to the couple tells X17online exclusively.

According to our source, "Reggie's mom just could not get over the fact that Kim had a sex tape. Reggie and his family are very conservative, and he told Kim that a marriage is never going to happen between them because of the tape." This is something that Kim's family has known for years, especially sisters Khloe and Kourtney.

Although Reggie did break up with Kim, the split wasn't because he cheated with January Gessert as it's been widely reported. X17online has learned exclusively that January "has been messing with Reggie's assistant for over 6 months." The day January was photographed leaving the the NFL running back's New York hotel, "she was really there to see his assistant, not Reggie."

Aside from the sex tape, our source claims Reggie had other reasons for separating from his reality star girlfriend: "Reggie is surrounded by a bunch of his single friends. He wants to be a party guy, hang with the boys and date other people."

As for how Kim feels about her ex now: "She's still crazy about him. If she didn't have the sex tape, she could have been Mrs. Bush."