Nick Lachey & Vanessa Minnillo Ring in New Year

The couple celebrate at MTV's bash, plus Jessica Simpson and John Mayer party in New York

The main attraction at the MTV’s live New Year’s Eve party in Times Square may have been the dropping of the ball, but for Nick Lachey and TRL host Vanessa Minnillo, the main focus seemed to be each other.

Just before midnight, the two – who’ve been dating for eight months – took their spot in the window facing down on the crowd and discussed the end of 2006 and the big bash going on below them for the MTV cameras. But off camera, things heated up between the lovebirds.

Lachey whispered into Minnillo’s ear and kissed her neck. The occasion appeared to overwhelm Minnillo, who responded by dabbing away joyful tears.

Minnillo later told PEOPLE she was pent up with emotion because “everyone that is important in my life is here. I literally choked up. I’m just so happy.”

Lachey complimented his date, who wore a gold sequined dress that swept the floor, saying, “Vanessa always looks gorgeous.”

At midnight, the couple kissed passionately. The whole room watched as they looked into each other’s eyes and, between sips of champagne, whispered and kissed some more.

Later the pair moved on to an after-party at New York’s Marquee club where they celebrated until after 4 a.m.

Meanwhile, Lachey’s ex-wife, Jessica Simpson, was also in New York to ring in the New Year – with her pal John Mayer.

The pair, who have been linked in the past, arrived together in the Hudson Hotel’s VIP room just after 2:10 a.m. and held court for about 40 minutes in a sofa nook across the room from Christina Aguilera’s entourage, which included her husband Jordan Bratman.

Simpson and Mayer also spent time together in the days leading up to New Year’s Eve. They were spotted having dinner at The Mercer Kitchen on Friday, walking around Barneys New York on Saturday, and hanging out at the Comedy Cellar that night.

As for Bratman and Aguilera, they partied into the night at the Hudson Hotel. Asked what it was like to see his wife sing for some one million spectators as part of ABC’s Dick Clark’s New Year’s Rockin’ Eve, Bratman told PEOPLE: “It was wonderful.”