Hayden Panettiere and her Heroes co-star Milo Ventimiglia have reportedly split, according to Us Weekly. “It was a lifestyle conflict,” said an unnamed source. “They were in very different places. They’re still on friendly terms. There are no hard feelings.” Apparently Ventimiglia, 31, prefers a quieter lifestyle than the much younger Panettiere, 19. The two have been dating for approximately a year. “[Hayden] is young. She likes to go out in the Hollywood scene and that’s not his style,” said the insider, who said that Ventimiglia had been busy “concentrating on work” at his production company Divide Pictures. Prior to Panettiere, Ventimiglia dated his Gilmore Girls co-star, Alexis Bledel, for almost four years.