Gossip Girl stars, Penn Badgley and girlfriend Blake Lively are getting very serious. Could engagement be on the horizon for the couple who does almost everything together?

This week on location at the Gossip Girl set at the Empire Hotel, our spies caught the 22-year-olds constantly touching, kissing and cuddling when they weren’t filming. An on-set source says, “Blake and Penn are so in love, it’s almost too much to watch! He sits in her trailer, keeps her company while she gets her hair and makeup done and walks her to and from the set. Penn will walk Penny (her puppy) for Blake when she can’t and he’ll run and grab her a snack if she’s hungry. He is the perfect boyfriend. She’s got him wrapped around her finger.”

When Blake had to go to Boston to work on her new movie, The Town, with Ben Affleck this week, Penn covered for her at her best friend’s book party in New York. Blake’s Sisterhood of the Traveling Pants co-star Amber Tamblyn released her second book and America Ferrara and Alexis Bledel all joined Penn to toast Amber with Akvinta vodka cocktails.

“Penn just fits right in with all of Blake’s friends. He filled in and no one thought it was strange at all. He is a great guy and America, Alexis and Amber love him. If Blake couldn’t be there, Penn was the next best thing. The girls think he’s adorable.”

Photo Source

MORE GOSSIP BETTY:

• Andy Roddick's Wife, Brooklyn, is His Ultimate Prize

• Lindsay Lohan & Samantha Ronson Reunite