A source said: "Nick proposed to Krissy on March 10, and she said yes. Krissy said Nick is the only person she trusts in the world.

They have a very deep connection." And a second insider claims the duo - who were apparently spotted kissing and holding hands outside a Target store in Georgia last week - have been romantically involved for some time.

The source said: "He's always been extremely protective of Kristina. [They] have blurred the boundaries between a platonic relationship and a romantic one for some time.

They've even been sleeping in the same bed!" Whitney - whose lifeless body was found in the bath tub of her Beverly Hills hotel suite on February 11 - took 22-year-old Nick in 10 years ago after his dad was sent to prison, although she never made the adoption official. Taking to twitter last week he appeared to confirm the rumours when he posted a picture of himself and 19-year-old Bobbi Kristina, and wrote: "Yea we got a little closer and what!!! (sic)" However, he has since denied there is any romance.

He told ABC News: "We're just close - just going through her mom's passing and grieving together." Tweet (less)