The two have been flaunting their love at tennis matches in recent months, starting with two appearances at Wimbledon in July and then at the U.
S Open on September 11 where the actress and the Oscar-nominated director, 49, caught a match between Novak Djokovic and Stan Wawrinka.
Sienna Rose Diana Miller was born in New York City, but was raised in London, England.
The 26-year-old songstress was still dating Calvin Harris at the time; she and the Thor actor started dating in June, just two weeks after she split from the DJ.Check her out as she attended the US Open yesterday in New York.Wearing a lightweight navy midi dress and sandals she nailed city chic and the perfect look for a sunny day court side. The actress, 34, has been dating Foxcatcher director Bennett Miller, 49, for a few months now, Us Weekly reports.The actress, who shares daughter Marlowe, 4, with ex Tom Sturridge, hasn't been shy about showing PDA with Bennett.In fact, the couple has allegedly been on several dates since his breakup with Angelina Jolie.