Hiya Rose. Divorce courts are not like criminal courts. Nothing is really proved. You say he committed adultery and he can sign and return the petition but deny it. Judge looks at it and as long as you both want the divorce thats that it gets stamped.
No one knows what the reasons for divorce except both of you and the judge and solicitors if you have them. Its not a matter for public record and divorce is private unless your name is Paul McCartney. So no matter what the reasons they are not detrimental to you. Just forget it and move on. Life is to short. Chris.
ChrisM outlines the situation in England & Wales, but it's rather different if you happen to be divorcing in Scotland. Here there is a strong burden of proof requiring at least one witness to divorce citing adultery or unreasonable behaviour. As a consequence 88% of divorces during 2006 in Scotland were based on separation.