Macaulay Culkin and Brenda Song have been together since 2017, but does all that time together mean they know each other’s careers inside and out? In this playful Cosmo Couples quiz, the two get super competitive, from Brenda nailing which co-star bit Macaulay’s finger (and kissing his booboo) to Macaulay calling London Tipton’s catchphrase a "layup"—yay him! Watch as they realize they both starred in Christmas movies, share their love for Jamie Lee Curtis, and rave about each other’s work in the sweetest way.