John Stamos is about to get busy in New York. The Glee guest star has joined the cast of the indie comedy My Man Is A Loser, which follows two men trying to be better spouses. Michael Rappaport and Bryan Callen play the husbands. Stamos will unsurprisingly play their playboy pal who tries to help them get their spark back. Mike Young, who wrote the script, is directing. David Goldin and Eric Bamberger of Step One of Many Entertainment are producing with Michael Becker of Imprint Entertainment. Loser starts filming in NYC this month. Also in the Big Apple, Stamos is joining James Earl Jones in Gore Vidal’s The Best Man, currently on Broadway. He will take over Eric McCormack’s role as presidential candidate Joe Cantwell in Vidal’s 1960 play about backstage jockeying in presidential politics. Stamos, along with Cybil Shepherd and Kristen Davis, will join the play July 10. He is repped by WME and Brillstein Entertainment Partners.