Lauren Silverman looked slim and radiant at the musical I Can't Sing, her first red carpet with Simon Cowell since the birth of their baby son, Eric Credit: David M. Benett/Getty Images

Lauren Silverman definitely has that X Factor. The new mom, who welcomed her second child on Valentine's Day, looked radiant at the opening night of the West End musical I Can't Sing at the London Palladium -- her first red carpet with Simon Cowell since the birth of their son, Eric

The New York City socialite, 36, showed off her slim post-baby body in a fitted black dress with zipper detailing around the hip and down her leg. Her skin was glowing, and she smiled as she stood alongside Cowell, 56. Click here to see more photos of their PDA-filled outing.

The American Idol alum, meanwhile, cut a dapper figure in a dark suit and crisp white shirt, which he left unbuttoned at the neck. He put an affectionate arm around Silverman's waist as they posed for pictures.

The happy couple have been in London for a few weeks now. After Silverman gave birth in New York City, she and Cowell took their newborn son to Miami for a little post-babymoon, and then jetted off to the U.K. (The new mom also has a 7-year-old son, Adam, with ex-husband Andrew Silverman, to whom she was still married when Us Weekly broke the news that she was pregnant with Cowell's child.)

"I was born to be a dad!" the former X Factor judge gushed of life with his son, who is named after Cowell's late father. "I look at him, Eric, and I think of my dad all the time, so it's a really good thing."