A fling has fired up between actor Josh Hartnett and model Katharina Alexandra Damm. The two met months ago at Hartnett’s home, where he hosted a party. Damm was charmed by the hunky actor, and they’ve stayed in contact while he films “Singularity” with Roland Joffe in Australia. Harnett has a way with models — he was linked to Victoria’s Secret angel Helena Christensen last year. Damm and a rep for Hartnett said “no comment.”