Josh Hartnett has dated some of the hottest ladies in Hollywood [Getty]
Ever wondered what it's really like when two co-stars take their love from the silver screen to reality? Think the likes of Brad Pitt and Angelina Jolie or Robert Pattinson and Kristen Stewart. Yep, us too. So thanks to Josh Hartnett who's opened up about dating his fellow actors and confessing that it's 'like trial dating'.
Josh, who's dated Scarlett Johansson and is currently in a relationship with British actress Tamsin Egerton, claims that romancing some of his former co-stars has had a negative impact on his career and made him "a lot of enemies" in Hollywood.
Asked about finding love on set, the 'Penny Dreadful' star told US ELLE : "I don't recommend it to young actors. You can make a lot of enemies in the business that way. But when you work with somebody every day, it's like trial dating. You develop a fantasy about them. It doesn't always work out, does it?"
Scarlett Johansson and Josh Hartnett in 'THE BLACK DAHLIA' [Rex]
The 35-year-old actor dated Scarlett for almost two years until 2007 after meeting her on the set of 'Black Dahlia,' and also dated Julia Stiles in 1999 after meeting her on the set of 'O.' He split from 'Les Miserables' actress Amanda Seyfried in June 2012 after six months of dating, and has also been linked to Kirsten Dunst, Sienna Miller, Rihanna and Penelope Cruz. So yeah, he's done the research.
The actor also suggested jealousy has been a problem for some of his famous ex-girlfriends. Discussing the secret to a happy relationship in Hollywood, he said: "Let them be on set whenever they want, with whichever co-star you're working with. Never say the scene is too sensitive. They get very suspicious."
Josh Hartnett and Tamsin Egerton in Poland last year [Rex]
But the actor - who began dating Tamsin "long after" he met her on the set of 'Singularity' in 2012 - admitted that none of his friends are willing to listen to him complain about dating some of the world's most beautiful women.
He said: "They want to hear all about what you're doing, but they don't want to hear any complaints. Back when I dated a few very beautiful, very famous girls, I said something once - it wasn't really a complaint - and my buddy said, 'Oh my God, my diamond shoes are too tight.'"
Scroll on to see our favourite stars who hooked up when the cameras stopped rolling...