The moments after childbirth were extraordinarily profound for Christina Applegate, who dropped her defenses and pulled daughter Sadie to her chest, a part of her body that she's kept closely guarded since her double mastectomy in 2008.
"I dropped my gown, which I don't do," the Hall Pass star, 39, says in an interview airing Tuesday on The Ellen DeGeneres Show. "This part of my body [her chest] is very private to me ... that's a real private place. A place that I don't have a good relationship with, let's say. But at that moment of pulling her out, I just tore that [gown] off."
It was a sign of just how open she was to her new daughter. "There's a room full of people that I don't know. Nurses and doctors," says Applegate – this week's PEOPLE cover girl, along with Sadie. "And she and I just lay there. It was the best thing that's ever happened to me."