Why wouldn’t Blake Lively want to be in a movie with Ryan Reynolds? While on the Friday, May 10, episode of The Tonight Show With Jimmy Fallon, John Krasinski, 44, joked about how he got the Gossip Girl alum, 36, to be a part of his upcoming movie, IF. The Office star claimed he used “emotional blackmail” to get Lively in the film, which also stars her hubby, whom she tied the knot with in 2012. “I was like, ‘Everybody’s doing it,’” Krasinski, who has been married to actress Emily Blunt since 2010, quipped. In the film about the world of imaginary friends, Lively starred alongside Steve Carell…