The TV stars were seen leaving Cecconi's in Los Angeles on Saturday night and Gavankar, 32, was all smiles in the passenger seat of 53-year-old Cowell's car.
Prior to this, the two were flirting on Twitter. Back in November, Cowell tweeted at the HBO starlet, writing: "Hello trouble." She wrote back: "...who me? #DefinitelyMe" He quickly quipped back: "Yes you."
Related: Cowell's Date Night with Carmen Electra
What do you think of this rumored romance: real thing or holiday fling?