If you remember in a very early episode, Gautam had openly mentioned that if he likes/loves anyone he will not shy to show his affection openly, damn the cameras.
The other day, Di was telling Karishma about having reached till 2nd base with GG which I don't think has happened here. It's a wild imagination of Diandra and she is in a fantasy hallucination world of her own.
When gautam likes someone, he has a tendency to display his physical closeness to that person, just like he is spotted sleeping on Punz's arms or stomach half of the time or with Pritam.
He has also totally cleared it out that he is just a friend and Di is clearly stalking him like a crazy (Darrr) style wannabe lover as is evident from the live feed. But the BB Edit team wants some masala and that's a different story altogether.
In my opinion, It's simply a case of affection, nothing more!