Diane Keaton has cornered the market as the mistress of the aging Hollywood lothario set onscreen. Having given the goods to Jack Nicholson in Something’s Gotta Give in order to reform the seemingly irredeemable swinger, now she’s matched up opposite Michael Douglas (as a selfish realtor drafted to care for his granddaughter) in Rob Reiner’s romantic dramedy. The thing with these projects is that audiences walk in knowing from the start exactly every beat and measure to be played, and there’s little room for improvisation from either Keaton or Douglas, so what’s the point? Opens wide July 25. PG-13. Not reviewed