“I would definitely like to do some dance moves with her. So I’d be like, ‘Can we do a training session?’ I’d train her on the court and she’d train me on the, I guess, dance floor.” – Washington Kastles player Venus Williams explaining to a reporter from local website Glittarazzi what question she’d ask Britney Spears when the pop star comes to D.C. later this month. Spears is performing at the Verizon Center July 31. Williams appeared at the Kastles’ home season opener Tuesday night. The Kastles tennis team won 21-18 in overtime over the Kansas City Explorers.