Adult superstar Karla Kush stars in “Infidelity 3,” the newest installment of the series, now available on DVD from Mile High Media’s couples’ erotica studio Sweet Sinner. The award-winning performer leads a talented cast of adult stars for acclaimed filmmaker Jacky St. James in four tales of couples grappling with outside temptations. The cast includes Alex Jones, Ana Foxxx, Mike Mancini,…