"P¬◊O!" says Lili. "You're doing it again
"Oh, right!" says Max. "Like you never play with yours!"
"Well, not all the time
!" says Lili. "You're totally obsessed!"
But later, we discover that there's nothing wrong with boys obsessively studying modal logic. It's just a phase they go through. And Dad even covers for Max when Mom finds her lingerie catalogue in his school bag.