Apparently your tenth birthday comes with a more refined understanding of the use of sarcasm. More conversations with Ms. B:
Me: So we got Marvin a new dog bed for upstairs. At first he wouldn’t go up there unless D or I were with him. But this past weekend he started going up there by himself, right at 10:00, every night whether D or I go with him or not. He’s like “I’m tired guys, I’m going to bed. See you in the morning.”
Ms. B: How cute! He’s making his own decisions! They just… (hand to her heart, melodramatic sob) they just grow up so fast.