Priscas

Hi, guys. I know I'm five years later to this discussion, but does someone got the joke when Lily says "Thanks for selling mine first, Dr. Chicago." It's after Cam says "I convince your daddy to wait on the apartment upstairs until I have enough time to sell your coat, and, if need be, even sell mine." I really don't know this "Dr. Chicago" reference. Can someone help me, please? ASAP, if it's possible. Thanks!