As it is now established that Léon is the Countess's son but not the Count's, and Florestine is the Count's daughter but not the Countess's, there is demonstrably no consanguinity, and they are free to marry one another.
既然现在确认Leon是伯爵夫人的却不是伯爵的儿子，Florentine是伯爵的却不是伯爵夫人的女儿，他俩不存在血缘关系，可以与对方结婚。