As Mark accepted his win for Best Actor in a Limited Series for his roles as twins Dominick and Thomas Birdsey in I Know This Much Is True, two of his three kids jumped into the video to celebrate their dad. Throughout Mark's speech, his 19-year-old son Keen (pictured above) clutched both of his parents in excitement as his 13-year-old sister, Odette, bobbed in and out of the frame.