I don't know what your husband's intentions or motivation are.
While you are trying to figure out the situation, you should know that just because he is home "all the time," doesn't mean he isn't having an affair at the office or online or by phone. It doesn't even have to be physical. It could be that he just thinks about the other person in a way that he wants to give her his heart, his body, or both. Or, maybe his relationship is with porn.
Whether or not anyone else is involved, my suggestion to you is the same. Encourage him to talk about his dissatisfactions and frustrations. What is difficult in his life? What would he hope for his future? What does he want that he hasn't been getting? Does he have some physical or sexual problem he hasn't previously discussed with you?
Listen with an open mind. Don't correct him if he shares his feelings. They are his feelings, not yours. Don't correct his view of your marital history, just try to understand that he is telling you something about his own experience. Go for marriage counseling.
Be the best spouse you can be.
