On set, Hayden Panettiere (Claire Bennett) and Milo Ventimiglia (Peter Petrelli) play niece and uncle, but off screen, it was another story. They dated a year before they called it off. Ventimiglia also dated Gilmore Girls co-star Alexis Bledel for three years.
http://www.popsugar.com/celebrity/photo-gallery/30449911/image/30456365/Milo-Ventimiglia-Hayden-Panettiere Via PopSugar.com
8. The O.C.
Rachel Bilson (Summer Roberts) met and fell for co-star Adam Brody (Seth Cohen) while filming The O.C. While the two get married in the last season, in real life the couple split up after two years of dating.
http://www.huffingtonpost.com/2014/08/29/adam-brody-ama_n_5737844.html Via HuffingtonPost
7. Gossip Girl
Leighton Meester and Sebastian Stan heated up the screen as Blair Waldorf and Carter Baizen in Gossip Girl. Their relations on the show led to a three year relationship in real life. The couple broke it off in 2010 and Meester is now married to Adam Brody and the actress is currently pregnant.
http://galleryhip.com/leighton-meester-sebastian-stan.html Via GalleryHip.com
6. Before Ryan There Was Penn
Blake Lively and Penn Badgley had some pretty steamy scenes while portraying Serene van der Woodsen and Dan Humphrey on Gossip Girl, but they were also hot and heavy off screen as well. The couple dated from 2007 to 2010 before parting ways and Lively is now married to Ryan Reynolds.
https://celebrity.yahoo.com/blogs/celeb-news/penn-badgley-calls-blake-lively-his-best-and-worst-on-screen-kiss-132131934.html Via Yahoo!
5. More Gossip Girl
Ed Westwick (Chuck Bass) and Jessica Szohr (Vanessa Abrams) shared smooches on and off set of CV’s Gossip Girl. The co-stars dated from 2008 to 2010.
http://www.popsugar.com/celebrity/photo-gallery/26291858/image/26291921/Real-life-couple-Jessica-Szohr-Ed-Westwick-partied-NYC-event Via PopSugar.com