It's not incomprehensible that ex-lovers can be friends but Ranbir and Deepika are not back together. In fact he and Katrina are going really strong.

"I have seen Ranbir-Kat twice at a newly-opened cafe at Bandra's Pali Naka and they are totally into each other."

But clearly they are not ready to accept to the dating/mating status just yet. Just blame a certain Salman Khan.