It’s Super Bowl Sunday on Tuesday: This week’s episode of NBC dramedy This Is Us takes you back to a time when Jack (Milo Ventimiglia) and Rebecca (Mandy Moore) rooted on the Steelers without having to worry about children. In fact, as you will see in this first-look clip for “The Game Plan” (Tuesday, 9 p.m. ET, NBC), they’re willing to let loose a bit — maybe throw back a shot or two to get this day started right. And how do they feel about starting a family? That answer may surprise you.