I hate to keep piling on however I agree that the sex should stop. Let me give my perspective as a guy: You were in a sex starved marriage by your own admission. He betrays you. Now he’s getting all the sex he wants and then some. Then he still leaves to go visit the OW. Basically you are rewarding him for his bad behavior. Not only is there no incentive to change, he probably thinks he should have done this sooner. He is still planning to leave and probably thinks he will stop by for booty calls at that point. Some of the best sex my W and I have ever had was during the worst part of our situation. The night before she moved out may have been the best. Emotions were high, it felt so right and I honestly thought the connection was strong enough that she couldn’t possibly leave. She did, 24hrs later. From the highest of highs to the lowest of lows in the span of a day. I’m only saying this to give you a guy’s perspective. I understand your fear. It’s paralyzing and you will try anything to make it go away. Letting him use you, abuse in my opinion, will eventually kill whatever self esteem you have left. You deserve better. Please consider stopping.