@Sosad,
Your husband wanted excitement and he got it! From a woman who is like his mother. (A psychiatrist would have fun with that.)
Of course he is going to lie about this. He's a fool. This woman is crazy. You are wiping up this mess and he won't help.
Stop talking to him about this woman and see a counselor who can put this marriage back together -------IF that is what you want.
PS How old are you and husband?