David Montelongo allegedly left "Flip This House" because of creative and personal difference with his brother and co-star, Armando Montelongo. David and his wife Melina also had some personal financial difficulties at the time that affected David's personal and professional relationships.
The Montelongo family has been in real estate since circa 2001. They comprised the San Antonio real estate team that debuted on season two of "Flip This House." David's wife was the marketing director of the company, and she and David decided not to return to the show after season three. The precise reasons why are still unclear, as of 2015.
During season three, on an episode called "The Cat House," the brothers feuded openly about a house riddled with cats. David thought the team should tear down the house, while Armando believed the team could renovate it. This was circa 2007; around this time, an investor sued David for failing to sign a partnership agreement and keeping the plaintiff's funds.
By 2008, the Montelongos experienced additional business setbacks related in part to the subprime mortgage crisis. Since most of the family's business credit was unsecured, and with the loss of revenue owed to the crisis, the Montelongos found it increasingly difficult to pay off their debts. Armando is among the parties that David and Melina owe in a separate, pending case.