It's going to be a tough road ahead for little Jack.
On Tuesday's episode of This Is Us, titled "Don't Take My Sunshine Away," Kate (Chrissy Metz) and Toby (Chris Sullivan) begin the difficult journey of caring for their son, who was born several months premature, and in ET's exclusive sneak peek, the seriousness of little Jack's reality is too much for Toby to bear.
In the NICU, Kate steals a few sweet moments alone with her "handsome" son before the doctor (played by Psych's Kirsten Nelson) swings by to do a few more tests on little Jack. "Still totally routine. We just have to continue to monitor all his levels, okay?" she says, assuring the new parents that this was all normal practice for preemies.
As the nurses set up a table full of scary-looking tubes and needles, Toby begins to get visibly uncomfortable with what's going on -- even after the doctor advises them to sing or talk to their son as they complete their tests.
"Toby, what should we sing?" an inspired Kate turns to ask Toby, who is looking a little worse for wear, immediately forcing her to go for it alone as she begins to sing "My Favorite Things" from The Sound of Music.
"You're doing so good, Button," Kate coos to little Jack, the nickname an endearing callback to her childhood pet name.
"We can't know if he's doing good. He can't cry. He's got that tube crammed down his throat," Toby says, overwhelmed by his son's situation.
But when the doctor is about to do a more invasive test on their baby, Toby cracks. "Can you not?" he pleads, fighting to get his words out. "Can't you get everything you need from the blood test?"
"Toby, stop it," Kate urges him to get a grip. Watch ET's exclusive sneak peek above to see what happens next.