Quote 1
"That's okay, right?" he asks as we leave the room together. "She does know about this, doesn't she?"
"Of course she knows," I reply. "Well, she kind of knows." Then, "Okay, no, she doesn't know." (10.107-108)
When Mia confides in Roger that she's really lying to her mom about acupuncture, he's uncomfortable about it… but he doesn't rat her out either. He lets her do her own thing. Mia, on the other hand, has no trouble deceiving her mom because she figures it'll be worth it.
Quote 2
"We had Oscar since before I was born. He was like a brother to me. I know that sounds stupid." (15.48)
Roger tells Mia about his dog as if he's part of the family. When Mia hears about his pet, she realizes that what she's going through is normal. Everyone who has ever had a dog or cat that died knows that—pets become a huge part of the family, so it's a big deal when they go.