There is another situation that is the most difficult to deal with, that is, your husband and classmates don't admit it, but they still contact behind the scenes and unite to cheat you. Even in the worst case, my previous suggestion should be done, and you can do it. Emotional things cannot be compromised. If your husband loves you very much and is responsible for his family, he won't do anything to hurt you. You should know your husband best. If the worst happens, the right side is in your hands. You can choose to forgive him or divorce him directly and so on. However, divorce should be cautious. This is no joke. It is not easy for two people to be together. Look before you leap. Trust is still a prerequisite. You have done everything you should do as a wife. As for the latter hypothesis, it may not have happened at all.
Judging from your supplementary information, this situation is not good and has been for a long time. You'd better call your elders and your close friends to discuss whether you want this family or have anything to do with that woman, depending on your husband's reaction and attitude. You have to observe for yourself what kind of person your husband is. You'd better talk to that woman before you do that. This kind of thing, whatever it is, there is nothing to hide. If your husband is a man, he should confess. It's so ambiguous. He's married. I don't know which is important. Really. As a wife, you just have to have the courage to cut the gordian knot in this matter. You don't know what your personality is. This matter is urgent, and the sooner it is solved, the better.