Regardless if he acted on the sexting. It is completely disrespectful to you as his wife to be sexting another women. You don't deserve that kind of treatment. If your husband is not willing to understand that it is completely wrong to behave this way, you should consider how this relationship is working for you. If he is willing to work on your marriage and improve his behavior that is great. Otherwise I would stand your ground and let him know its unacceptable.

Agreed. It's about loyalty. You live together & have a life together. You are partners in life & that is just unacceptable to be sexting or touching another woman in any way that isn't platonic.