Boston Bruins fan Krasinski tweeted a video with a surprise cameo by David Denman, who played Pam's ex on The Office. "Ha. Ha. Ha. Well played. Just be careful he doesn't leave you at the game," replied St. Louis Blues fan Fischer. Earlier, Fischer tweeted her disappointment over her former "boss" Steve Carell supporting the Bruins.UPDATE: Fischer gloats over the Blues' victory with a "Gloria cake."