Dave Franco says the weirdest rumor he ever heard about himself is that he was dating Zac Efron.

The 40-year-old actor - who has been married to Alison Brie, 42, since 2017 - revealed an ex-girlfriend called to question him about his relationship with his Neighbors co-star after a photoshopped image of them appeared online.

Speaking on the Call Her Daddy podcast, Dave said: "This girl that I was kinda seeing at one point reaching out and being like 'hey, what's this all about?' and it was this photoshop of me and Zac Efron at like a basketball game where we're getting like really cozy together. Then there were all these headlines that maybe we were dating. And I think that had some legs too."

Dave also confirmed that he was responsible for Zac, 37, dislocating his thumb while filming a scene in Neighbors where Zac had to grab Dave's crotch.

He said: "It definitely wasn't because my penis was hard. Yeah. I'm trying to remember if I was wearing a cup and he came in just really strong. I think it was a dislocated thumb to be fair, but it, it happened. There's a scene where I think we're both grabbing each other's crotches at the same time. And I just think he came in with enough force from the wrong angle.

"The character actually, now that I think about it, not to walk through the whole synopsis of Neighbors in this interview, but he grabs my crotch and we're both holding on like who's gonna let go first and then my character actually to get him to let go, I have a trick where I go Zen and I know how to get hard on cue. So, I do get hard in this hand. That's what makes him let go."

Zac previously discussed the incident during a 2014 episode of The Tonight Show Starring Jimmy Fallon, joking that he broke his hand because Dave had "balls of steel".