Heroes stars Hayden Panettiere and Milo Ventimiglia don't have the power anymore to keep their relationship a secret. The two had had an open secret relationship for months now and finds it tiresome to continue hiding their love.

"They were tired of avoiding questions and of all of the effort of keeping it secretive," a friend of the 18-year-old actress who plays cheerleader Claire Bennet in the top-rated TV series.

Aside from the 12-year age gap, Panettiere also reportedly didn't want to let the public know of their relationship because she was worried about her reputation. "She didn't want people thinking she is a 'ho' because she jumped from one relationship into another," the source tells Us magazine.

Ventigmilia apparently had a crush on his co-star while she was still dating Stephen Colletti. "He always had a crush, but really let her know the minute she broke up with Stephen."

The source also adds that Ventimiglia has her mom's approval because "Milo is such a good guy, honest and sweet." Another source also says that Panettiere is mature enough for him because she is really "like a 30-year-old."