The Insider.com

Zac Efron and Taylor Swift take to the Ellen show today to promote their new movie, The Lorax, and in the process deny they're diddling.

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"We are not a couple," Taylor replies when Ellen implies the two are dating. "He's awesome, we are not a couple though. You hear people get together when they're shooting movies, co-stars. But not like animated co-stars. You know what I'm saying?"

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But that doesn't deter Ellen from pursuing this line of questioning, asking about their Valentine's Day plans. Which is when Taylor totally throws Zac under the bus by outing the fact he was on a date while she was having a "girls night."

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Although by that point Zac had already put himself on display by bringing in an underwear baring photo, taken while he was getting a new tattoo and flashing some of Ellen's signature undies.

And after you watch that video, get a quick sneak peek of the two performing a fun little duet!