He might not consider it cheating to be honest. So I think maybe he doesn’t consider it being dishonest that he didn’t share it.

My t said, and I agree with her, that even though spouses should be honest with each other, there is no need to be an open book about every little thing. Everyone deserves privacy especially about their past.

Unless it’s something very relevant to today’s life like criminal history/incarceration or illness/disorder or something contagious or substance abuse addiction, I feel there might be no need to disclose. When people meet later in life it’s only understandable they had all kind of relationship experiences, some of which they might not be proud of and wish they didn’t do.

Not all of it needs to be known and revealed especially if it makes no difference today. I’d focus on how he behaves now. How transparent he is and how he lives his life and his he treats you. If something bothers you in his behavior now, address it but don’t dwell on whatever happened years ago before he met you or whatever third parties do.

This is just my take on it.