Okay, I don't think this was posted on a site or on a com, I know it was a WIP, the author posted on her LJ in snippets.
Rodney was captured by a society that holds tournaments giving away bachelors as the prize. He was chosen because this society feels that blue eyes and fair skin are the height of beauty. The team decides that John will enter the tournament to compete. Rodney has amnesia and is made to pose for a poster in silk-like lounge pants. Also the prince of this society seemed pretty smitten with Rodney and molested him sexually.
There was also a waterfall bathing scene were Rodney was the show. He was drugged by the prince and forced to masturbate for him.
John's pretty much going crazy with jealousy but it's definitely pre-McShep.
Yay! Found! Link in the comments