It is highly unlikely that if he was dishonest enough to cheat on you that he would be honest enough to tell you.
Cheating is a form of dishonesty... So you cannot make that assertion. He may have truly loved this other person and thought that what you do not know will never hurt you.
Sass as you don't know my husband, as usual have absolutely NO idea what you are talking about!
As I said my husband is the most honest person you could meet, uncomfortably so, as I have said before, possibly because he appears to have Asperger's syndrome. Besides which, he wouldn't have had time to cheat on me, even if he felt inclined, as academic work was his main love, and the only day he took off from it, was Christmas Day. He even took it on holiday, much to my irritation.