#6. Adrienne Bailon
Adrienne and Rob got together in 2007, just as Keeping Up with the Kardashians was beginning to become the phenom it is today. Naturally, Adrienne made regular appearances on the show during the course of their relationship, as she was the focal point of Rob’s life at the time. They even got matching tattoos of each other’s names. Though Rob seemed to be completely enamored by his lady love, he admitted that he was unfaithful and that was what ultimately ended their relationship in 2009.