Cissy Houston Blasts Bobbi Kristina's Alleged Relationship

Bobbi Kristina Brown was spotted kissing the young man who was raised alongside her by Whitney Houston. Now, Cissy Houston is saying what they did was "incestuous." INSIDE EDITION has the details.

Whitney Houston's daughter Bobbi Kristina was videotaped walking hand-in-hand with the man she's seriously dating. And get this—they were raised as brother and sister.

22-year-old Nick Gordon and Bobbi Kristina certainly look like a couple in love on the video, stopping to kiss on the way to pick up pizza in Atlanta.

But the relationship is reportedly splitting the Houston family just one month after Whitney's death. Whitney's mother, Cissy is quoted as telling friends, "What they're doing is incestuous."

Bobbi Kristina and Nick Gordon are not blood relatives. But Nick was raised by Whitney from the age of 12 because he had a troubled family. He's sometimes called Whitney's "secret son." Gordon stood close to Bobbi Kristina at Whitney's funeral.

They were apparently dating before Whitney's death. Last November Bobbi Kristina tweeted: "I love sleeping with big brudder :) only person that helps my insomnia!! Hah :)"

Nick Gordon denied they were dating just two days ago, saying they are "Just close...grieving together."

But now they're both tweeting defiantly: "Yea, we got a little closer and what!!! All the haters that don't know us or the real story can unfollow me. I don't give a (blank)."

Published reports say that Nick has even proposed marriage and gave his girlfriend a ring just last week.

It's only her second serious relationship. Her first serious boyfriend, Zach Jafarzadeh, told INSIDE EDITION he believes that Bobbi Kristina is still confused and broken-hearted over her mother's death.

"I really hope that they're okay because she really loved her mom. That was her idol. That was her best friend, her mom. They really had a very, extremely close relationship," said Jafarzadeh.

Now she's seems to be taking comfort in someone she's trusted her whole life.