Tinsley Mortimer‘s show for the CW wraps shooting in New York this week, but she’s not going out without a fight. At Monday night’s Guest of a Guest party at 675 Bar, Tinsley got into an argument with wannabe socialite Devorah Rose after Rose insulted her boyfriend, Prince Casimir Wittgenstein-Sayn. “Rose had been telling guests that he has no money, and that Tinsley pays for his apartment. Tinsley denied it,” a spy tells Page Six. Says CW exec Justin Rosenblatt of the show, “It’s entirely unexpected and in the moment. The storylines all arose organically. We didn’t have to steer anyone cause they have enough going on in their lives.”