This can also happen if the lady they kissed got waylaid by someone else. I see it happen all the time. To keep my established villages self-perpetuating, I make sure about half of them are breeders. So whenever I go into those games, one villager of each sex becomes the Object of Attention and all the other breeders of the opposite sex keep walking up to embrace (and sometimes run away!) from the OoA. Mind you, they actually let the villager do work when the game is off, but when it's on, it's smooch city! LOL