Hi, I'd like to help you with your question.
It sounds like your husband has made a big change and is concentrating on repairing your marriage with you. That is wonderful. But it is very understandable that you still feel concerned about the affair(s) he had.
When a spouse has an affair, it can cause a number of strong feelings to surface. Anger, sadness and jealousy are common. It also is a blow to your self esteem. Your husband has picked someone over you. You want to know what they have that you don't. It is not unusual to feel this way when your self esteem has been damaged.
Also, your husband went outside of your marriage and brought someone between you that did not belong. So you are curious about who they are and what they are about. This is also a very natural response.
It is ok to ask your husband for details about what happened. And if he is willing to oblige you, that shows he cares about you. Honesty and openness are the two most important parts of recovery from infidelity. But before you consider talking to him about how you feel, think about how the information is going to affect you. What will you do with it? How will it affect how you feel about yourself and your sex life with your husband? How will it affect your self esteem? Hearing about the other women usually will make you feel worse, unless you have support to help you sort through it. But if you are feeling distressed by it and need to feel closure, it is ok to ask. Just be sure to have someone you can talk to to help you sort out how you feel.
You asking these questions will not make your husband want to go back. He was not cheating because of the sex, he was cheating because there was something in him that he was not dealing with. But it sounds like whatever made him choose cheating over working out his problems has been dealt with.
The best way to help yourself through this is to get support and learn more about the effects of infidelity. Here are some resources to help you:
Not "Just Friends": Rebuilding Trust and Recovering Your Sanity After Infidelity by Shirley P. Glass and Jean Coppock Staeheli
How to Help Your Spouse Heal From Your Affair: A Compact Manual for the Unfaithful by Linda J. MacDonald M.S.- for your husband
Intimacy After Infidelity: How to Rebuild and Affair-Proof Your Marriage by Steven Solomon and Lorie Teagno
You can find these books on Amazon.com or your local library may have them for you.
If you feel too overwhelmed to deal with how you feel, consider short term counseling or an on line support group. They will provide support and guidance until you feel healed. You can also talk with someone here on JA on an ongoing basis. Experts sometimes work with people to help them resolve a specific issue. You can either continue a thread you start with an Expert, or request a specific person.
I hope this has helped you,