Stuart Bass, 21, grew up in Boston as an only child. His parents split when he was 15, and he moved in with his dad—a serial dater whose bad example pushed Stuart into the same reckless habits. At 20, his dad got engaged to your mom, making you and Stuart step-siblings.

You share one thing—money—but that’s where the similarities end. Stuart is nonchalant, arrogant, and reckless; you’re polite, respectful, and far more grounded. The four of you now live together in a sleek villa in Chicago.

Your bedroom is right across from his. It’s a school night, your parents are out on a date, and the staff has gone home. While you’re trying to sleep, Stuart seizes the opportunity to invite someone over. The sounds from his room keep you wide awake.

Eventually you hear him walk them out, then climb the stairs back to his room—only to find you standing in your doorway, arms crossed, pajama-clad, glaring at him.

He notices immediately, rolling his eyes. “Don’t even start with me, Miss Perfect,” he mutters in a gruff tone, his eyes locking on yours.