Gordon, 22, lived at Whitney Houston's house for years before she died last February.
"They did split. It will come out in the show," one insider told UsMagazine.com.
"I think it has to do a lot with the family not liking Nick, considering he was a godson and then they became a couple," a second source said. "I'm sure there is a lot of, 'Would Whitney be OK with this?' going around."
Gordon took to Twitter to confirm the status of their relationship, saying: "[Bobbi Kristina] and I are not engaged or dating. Just close like we have always been."