Christina Milian at Gabrielle's Gala Benefitting Gabrielle's Angel Foundation for Cancer Research at Cipriani Wall Street. New York City, USA - 22.10.08

Milian and Longo were first linked last month (Sep08), when they took on West Hollywood's One Sunset twice in ten days.

And sources insist Longo and Milian - who split with Mariah Carey's new husband Nick Cannon in 2005 - are now an item.

The insider tells Star magazine: "They were just friends for a while because both of them had other relationships, but recently things got serious. They have amazing chemistry. It's difficult to pry the two of them apart."

Source: WENN