Other social media users were quick to jump on the posts, speculating that the two actors might actually be an IRL couple.
"I think Zac Efron and Rebecca Ferguson must be dating, and I couldn't be shipping it more," one fan tweeted.
"I lost my mind because of the internet," he explained, "I'd read 30 positive things and one bad thing, then I'd harbor that bad thing. We would swipe right for you (and your monster abs) in a heartbeat.
She told that she purposefully edits Efron from her images because of his fame, although she has posted a few photos with the hunk.
Earlier this week, Zac 'grammed a picture of the two stars on set, where Rebecca is pictured in a ballgown and he is wearing a tux.
She's staring intently at him in the photo, and he is smiling at the camera, seemingly unaware of her gaze.
They reportedly giggled and snapped pics with one another all night.
Ch-ch-check out some of their flirting before and during the big show on Instagram (below)!