Zayn Malik, Gigi Hadid ... Rebound Date

Something's definitely going on between Zayn Malik and Gigi Hadid ... they partied together Tuesday night and security did their level best to shield them from photogs.

They showed up at The Nice Guy in WeHo at around 10:30 PM where they entered from the back so there's only a fleeting glimpse. Two hours later they resurfaced and left together.

Gigi hit up the same spot Sunday night at Justin Bieber's after-party, where she was photographed leaving in a SUV with Zayn.

Anyone confused?