Fiona Barrington was a human female who once lived on Io, and was the first girlfriend of Arnold Rimmer, although Arnold never actually "got lucky" with her. Rimmer once thought he'd got lucky, but it turned out that, during their greenhouse tryst, he'd had his hand in warm compost the entire time. Rimmer told the story to Lister, who was able to relate the story to Rimmer to prove that he knew him when erased from the timeline by The Inquisitor. ("The Inquisitor", Series V)