"It fell into place quite quickly and we're all super excited for them," said Amanda Setton, who plays catty Penelope Shafai on the show.
So was she surprised by the on-set hookup? "When two people that you know separately get together, you're always like 'Oooh, what's that about?' " Setton told PEOPLE at the H&M Celebrates Matthew Williamson party in New York Tuesday night. "They really balance each other. I'm just happy that they're happy."
According to Setton, she will not be joining the ever-growing list of costars who have found romance on the Upper East Side set. "I've had my own love for a long time," she stated coyly.
One thing she did share is that the rest of the season of Gossip Girl will be filled with the usual drama. "I can tell you that the last two episodes of the season are really juicy," Setton said. "I always say that, but it's true!"
She added: "I am going to seriously up the meanness as I always do. I promise I'm not vicious in real life. I really swear."