A boy...
Rory wondered if Uncle Lenny wants a boy. But she didn't understand what made Sidney so scared about it. Knowing her, she might be worrying if she would lose her figure if she has another baby.
But thinking about having another kid, she got scared too. But she cleared her throat.
"Liam says he wants a boy too! What's with the Roberts? Grandma Roberts could not stop talking about her desire of having more girls in the family, but the men... They want boys!" Rory laughed mostly to veil her fright. "I guess, everyone wants what they don't have."
Only after saying what she did, did Rory realize that she brought up grandma Roberts to Sidney. Grandma Roberts is not at all fond of Lennon's family as it reminds her of grandpa Roberts' unfaithfulness. Bringing her up might have hurt Sidney.