In general, all wrasse should be met with caution. Although I have never owned a whip fin, much less a fairy wrasse long enough, I've had the most luck with smaller wrasse (not six line) but in particular cryptic (pink streaked) and tanaka pygmy or possum wrasse. Being of a smaller size, their temperament is very shy and seclusive in a big tank setting whereas the normal adult 4-5" wrasse (fairy, flasher, pencil,) will typically display aggression per their growth/age. That being said, you can certainly try. If you decide to keep a couple, I would try introducing 2 at the same time, not either/or. Hope this helps Brad...