I think the main thing that you should be concerned about is that if your husband is having sexual relations with another man, would be the disease factor...This is serious...If you have any proof or big questions in your mind, have him wear a condom...How you go about doing this is another problem...
This is something that the two of you must talk through...How you are going to handle it I really don't know...I try to put myself in this position and like you, I would be devastated...One thing I do know, at least it is my opinion, is that a woman can never battle another man for satisfaction in sex with her partner...Man on man will win...
What you said to him is what you felt in your heart...You are probably right...I am sorry but I cannot advise you on something that I know nothing about...I send you all my love and best wishes...
Caroline