Well, in NY adultery is not illegal. However, obtaining a divorce is not so difficult. There is an adultery standard for a "fault-based" divorced. It's just one of many different reasons that you can obtain a divorce. Of course you do have to prove this, which in some cases may not be so easy. However, many states in the US are adopting "no-fault" divorce, and NY is one of them. Meaning, you can file for divorce and claim "irreconcilable differences". Because of that, divorce has grown tremendously in NY, and I believe the statistic is now that almost half of all married couples will eventually divorce. This is frightening. I don't think adultery should be criminalized because of the stigma associated with a criminal record. In the US (especially NY) it is really hard to find a good job with a record. it is even harder to find a job where a manager or owner would actually respect you and not treat you like dirt. However, morally, I believe adultery is wrong. Hope this sheds some light on adultery in the US (specifically NY). (PS, I'm a law student).