Despite their busy schedules, both Katie and Jamie managed to make some time to celebrate. The 40-year-old kept her birthday outfit casual and wore a colorful floor length sweater on top of a basic grey tee with high-waisted blue jeans.
Katie accessorized with a large black leather tote bag, Gucci booties, a silver necklace, and attempted to keep a low profile in a pair of dark sunglasses.
Jamie was spotted walking into Manhattan's well-known restaurant, Serendipity, not too long after his girlfriend, wearing a long brown pea coat with a grey scarf, light denim jeans, and white sneakers. He competed his look with a pair of black Privé Revaux sunglasses.
The mother-of-one was spotted wearing a large diamond ring on her left pinky finger in October on the set of her upcoming film The Secret, but Katie's rep told People at the time the ring was not an engagement ring. “Katie’s not engaged to anyone besides her fictional movie fiancé, played by Jerry O’Connell,” the rep said.
Nevertheless, the couple seems to be very happy. "Everyone knows they are dating, but they still want to keep it private. They only spend time together at home and are extra careful. But lately, they have been more social together. They often go to restaurants for dinner dates, or to hang out with friends,” an insider told People.
The Law Abiding Citizen actor and Katie were first seen together in 2013 in the Hamptons, a year after she and Tom, 56, ended their marriage.
What do you think of Katie & Jamie's relationship? Let us know in the comments!