Help, husband wants a divorce after 23 years for stupid reason?

We have been married for over 23 years and have 2 adult children. He is asking for a divorce so can try things sexually that I have refused before he gets too old to even have sex. That is the reason he is giving me which is just stupid. Nothing else is really wrong in our marriage we get along great and have a fairly active sex life (have sex a few times a week). He even told me that wants the divorce to be as amicable as possible and would feel horrible if we at least could not remain friends. His reasoning is that its better to divorce and do this then cheat on me and break his vows. So says be better if we were to divorce and then he can explore the things that I have turned down all of these years sexually. They are nothing real extreme like as in not BD or SM stuff. He swears not using this as some sort of threat to get me to do something I do not want to do. That is why thinks it best to divorce rather then cheat or keep asking since its obvious never going to happen with me. Its not that he brings the subject up all the time that's why it shocked me that has said this now. In fact last time he even asked for one of these things was months ago. Rather then avoiding the question that you might have its oral and anal that he has asked for since we gotten married. Like said he does not ask all the time but I have told him that will not do either. He has done oral on me and says he enjoys it so does it fairly often. I just think its disgusting as is anal that's why have always said no. Still am in shock that he is willing to just throw away all these years for something so silly. Like said we talk every day, tell each other we love each other daily, hold hands when out and many other romantic things. I love him with all my heart and he says that loves me as much as well.