Most behavioral problems can be solved with a lot of patience. The suggestions given by a number of people, like keeping the rugs rolled for a while until they adjust are excellent, I just wonder if he is willing to put up with it. But if the boyfriend is so adamant that he hates the cats perhaps rehoming is the best solution (for the cats of course). I think that you can say that you prefer cats to dogs or vice versa but hating them? Personally if someone said he hated my cats then I would ask the cats to kindly show him the door.