There's no denying there's something special between Cole Sprouse and Lili Reinhart!

Riverdale star Skeet Ulrich chatted with ET's Deidre Behar at the premiere of Netflx's True and the Rainbow Kingdom in Los Angeles on Thursday, where he dished on his co-stars' "great chemistry."

WATCH: EXCLUSIVE: 'Riverdale' Romance Rundown -- All the Details on Season 2's Love Interests!

"Well, I know they spend time together because they're at work all the time together," Ulrich, who plays Sprouse's TV dad, FP Jones, told ET. "But, I'm not surprised. They have great chemistry and they've been at our house with a lot of the Riverdale people and they always enjoy each other's company. So I wish them the best."

So do the on-screen couple have a special connection off-screen?

"It seems like it. It seems like it, yeah," the actor expressed. "You just hear them talking to each other like they've been best friends for 20 years. So it's a good sign."

WATCH: EXCLUSIVE: 'Riverdale' Season 2 Sneak Peek: Archie's Going 'Darker' -- Plus, Check Out the Season 1 Gag Reel!

Sprouse and Reinhart have yet to confirm they're more than friends. Earlier this month on Sprouse's 25th birthday, Reinhart dedicated a sweet message to her on-screen beau.

"To the man who has showed me more beautiful places in this past year than I have ever seen in my whole life. Happy birthday, Cole. Thank you for all of the adventures and here's to many more ?," the actress wrote on Instagram.

Meanwhile, Sprouse's most recent Instagram post is a gorgeous photo of the blond beauty.

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ET spoke with the Riverdale cast at San Diego Comic-Con last month, where they teased new love interests for their characters.

Find out who's pairing up and who's calling it quits in the video below!