why are jake and bill annoyed by the telegram from cohn that says he will arrive thursday

After breakfast, Jake receives a telegram while he sits outside with Bill. Cohn writes, in Spanish, that he is coming Thursday. They write a telegram back and tell him they are arriving tonight.

Hemingway draws numerous parallels between bull-fighting and sexuality. The greatest is one that Mike points out; Cohn is similar to the steer, a castrated, weak animal ruled by the powerful, violent bulls. Just the like the steer who is kept from joining the herd in the unloading, Cohn is the constant outsider, the Jew in a crowd of Protestants and Catholics, the emasculated follower of the masculine Brett.