It sounds as if your relationship is one in name only. His problem and the multiple infidelities is really not a justification assuming that there is a mutual desire to reconciliate. As I see it there are really two issues and to modalities to attempt to solve the problem.
First and most importantly is there a desire by both parties to maintain the relation. This would be done in exploration in marital therapy. A good therapist can be obtained from www.aamft.org . If the answer is no there is no sense in trying to solve the sexual problem and work on the marriage.
However if the answer is yes the sexual problem can be solve with some work with a competent sexual therapist. A good one cane be obtained from the www.aasect.org .
Whatever the case staying in limbo is a terrible solution. Again In answer to your first question, infidelities by one spouse does not justify similar action by ones mate..Good luck.
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