How long have you been married Op?
I have a friend who has been married 26 yrs, since they were young. Her husband goes away on work trips often. She recently told me she would be amazed if he hadn't had sex with others during all that time. I was shell shocked, she was non plussed. She then told me she herself has been attracted to other people and if they had fancied her too, she would have slept with them . She is unhappy but stuck due to finances. She has an escape plan but it involves what her lovely beloved Dad and what he will leave for her in terms of finances and, has put in place for her her so, she is bidding her time.
EVERY man i EVER worked with and known , in over 35 yrs of working, since the late 80's and present day, who is married; has slept with co workers and also hit on me and others, even present day. Even today, i have experienced this and witnessed this. I know someone who had a baby in the 90's ( the female) as a result if an affair and, agreed to keep it secret until the chid was 18 as; the father was married with 2 young DD's at the time and was a respected solicitor. She was paid a generous amount of money each month to stay within the agreement that their shared child; would only be revealed when his then own very slightly older daughters had been to uni , then his wife could know and leave if she wanted, once his daughters were educated and ready for the world. During this whole 18 yrs time he maintained regular with contact with the child who was a son , his only son.
I guess i am saying i do not know what marriage means. As a younger woman i always rebuffed these sleeze bags, even though i fancied them. Now, as an divorced woman who was always faithful, i see sex differently. I see it as just sex. So do i ask if they are married? Honestly no. It suits me.
Some, feel it ok for their spouse to sleep around, if it protects their own interests and marriage. They will turn a blind eye to safeguard what they have ;others do not. I suspect it is unrealistic to be monogamous for life. I do not know what to say Op, this is a horrible time and discovery for you.