VIDEO : What is Going on With Rob Kardashian and Blac Chyna?

It's not everyday you date your little sister's boyfriend's ex-fiancé...but it seems like Rob Kardashian's is happy with Blac Chyna.
A source says that Rob has been "taking better care of himself since his health scare and Chyna is helping him continue along that path."
As for how the couple first sparked the fire to their new romance, the source says, " Blac Chyna was friendly with Rob when she was good friends with the Kardashians. Rob always thought she was pretty hot."
Still, the amount of drama that's already stirred up between Chyna and the rest of the Kardashian-Jenner clan?who think she might be "preying" on Rob during a "time of weakness"