Lion Man's Captive

Anya was on her way home from a fantasy convention when the aliens landed-well, alien ships filled with nano-bots bent on terra-forming Earth to suit the aliens that sent them-starting with eating everything in sight and ending with the introduction of flora and fauna from their own world. In short, alien genesis. There was only one actual alien, and Anya ran smack into him trying to escape the nano-bots that ate her clothes.
And once he'd captured her he seemed really determined to keep her. She didn't know what he had in mind, but she didn't think it was entirely due to the steamy looks he sent her way.