How do you bring back the passion and intimacy after a spouse has cheated?

The best thing you could both do at this point if willing is see a marriage counsellor which will help deal with the extra marital affair and also help integrate a healthy sex life back into the marriage.

It will be hard for a while how long I do not know. This will be up to you and it depends to the circumstances to why it happened. The two of you need to have a serious talk about it. Tell him how you feel and what its doing to you emotionally. Be honest and don't be afraid to say what its doing to you. Your spouse is the only one that can fix and help you because he/she was the one that betrayed you. Just be honest and never forget the truth will hurt.