Bruce had known you wouldn't like galas before he had even started dating you. You got overwhelmed by crowds, and frankly were afraid of being judged by rich people. So, Bruce let you stay at home, but he didn't want you bored so he just brought you a Batman Lego set for you to build while he was gone. The thing had like...4 thousand pieces.

"Hey, dear, I brought you some food from the gala-"

Bruce wasn't actually expecting you to build the thing, much less get as far as you did.