Its tough to have to go through the one you love finding love or sex with someone else.
If you loved him before the affair, you can love him after. If you simply lusted for him before the affair, it takes much more effort to change the lust into love, but that too is possible. It wasn't all that long ago that marriages between two children were arranged by their parents before the children could even walk. Those men and women in arranged marriages found love for one another.
Watch the movie, "Fireproof" with your husband. Buy and follow the book, "The Love Dare", a companion book to "Fireproof". Buy the books, "The Proper Care and Feeding of Husbands" and "The Proper Care and Feeding of Marriage." Follow their advice and suggestions. If you do, your husband will wonder why he ever strayed. I've seen husbands and wives save their marriages by following the suggestions in those books.
Men and women have different views of sex. The worst thing you can do is to "cut him off". One of the best things you can do, to keep the eyes from wandering, is to make sure what he was looking for elsewhere he finds at home. Most men I know would never go out for hamburger if they had filet mignon at home. Or if you would like, most men wouldn't go out to drive a volkswagen beetle if there was a lamborgini in the garage.
Good luck to you and yours.