"HaLo" Finally official

After months of denying a relationship, Hayden Panettiere and Milo Ventimiglia are finally a bona fide couple, according to a family friend.

So says People, which reports that "HaLo" is going strong after a December trip to New York, when Milo chilled with the Panettieres.

"Hayden's mom adores Milo. She thinks he's so cute... She tells her friends that he's her boyfriend. She's very proud."

As for the couple itself, they're "very affectionate and very comfortable around each other." Reps say they don't comment on Panettiere's personal life.