If mr. x is coming to the house and she knows she likes him then he shouldn't be coming to the house. She needs to distance herself until you have a chance to work on the relationship. If she has said she wants to work on you as a couple then find a marriage counselor in your area to address reuniting the spark. Couples find it difficult all the time to keep a relationship going. You have to have strong boundaries in your house. Work together to develop boundaries in your home that do not make you feel so uncomfortable. If she wants the relationship she will learn that boundaries are necessary to be a healthy couple.
I would speak to her immediately about finding a professional. Then identify the rules of your home. Limit her contact with mr. x. Let her know how her behavior makes you feel. Work on all of these goals as a couple. When you work together you will see how motivated she is
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