As Georgie and Jim start fixing up an old car, Georgie worries Connor is being left out. Meanwhile, Audrey and Mandy find it a challenge to work together on decorating CeeCee's nursery.
Title Reference: "An Old Mustang" refers to the car that Georgie and Jim try to fix up in the garage.
Georgie sings Soft Kitty to CeeCee to help her fall asleep. The song was first established on The Big Bang Theory as something Mary sang to Sheldon as a child, and later appeared on Young Sheldon when Sheldon sang it to baby CeeCee in the episode "Teen Angst and a Smart-Boy Walk of Shame".
Georgie tells Jim about the childhood trip his father took him and Sheldon on to Cape Canaveral to see a space shuttle launch, which happened in the Young Sheldon episode "Cape Canaveral, Schrodinger's Cat, and Cyndi Lauper's Hair".
Georgie: [sings] ♪ Soft kitty ♪ Warm kitty ♪ Little ball of fur ♪ Happy kitty, sleepy kitty ♪ Purr, purr, purr. ♪ Mandy: That is so sweet. Georgie: I'm trying to get her to sleep so we can fool around. Mandy: Less sweet.
Mandy: I think it's sweet they have something to do together. Audrey: Your dad always hoped to rebuild the Mustang with Connor. Mandy: Seriously? Dad and Connor? Audrey: Go look in the attic. There's footballs, baseballs, fishing poles, bows and arrows. Your father tried everything. He did not give up on your brother. Mandy: So what happened? Audrey: He gave up.
Audrey: Have you seen that new Friends show? Mandy: No. Audrey: All they do is drink coffee. Who can drink that much coffee? Mandy: I don't know. Audrey: And their mugs are like soup bowls. Is that a New York thing? Mandy: Mom, I don't know. Audrey: I miss Cosby. He was a nice family man.
Audrey: I was thinking of taking CeeCee with me to the mall today. Mandy: Oh, that'd be a huge help. Thanks. Audrey: You hear that, sweetheart? Just you and Grandma. Mandy: Wait a minute. We discussed this. You're not getting her ears pierced. Audrey: Oh, come on. People keep thinking she's a boy. Mandy: I don't care. Audrey: She won't remember it. Mandy: Yes, she will, 'cause it's the last time she'll ever see her grandma. Audrey: Fine. Jim: While you're there, I could use some socks. Audrey: I'm not going anymore.