Am I being unreasonable?

We have been married over 23 years are age 45(him) and 48(me) have to adult children 21 and 22. My husband wants a divorce, in my opinion a stupid reason. He says that wants the divorce rather then cheating on me. It boils down to at least two things sexually that I have always refused. First is give oral to completion. I do some oral but only for a little bit and no way want sperm in my mouth. He gives me oral fairly regular to orgasm but he says that he loves to do that for me. The secon thing is anal and just outright refuse to do that. He says ther are other things that he has tried to get me to try but have shot him down. When asked why now the reason says that had hoped would change mind someday but gave up on that idea years ago though has still asked every once In a while. Also reason waited for youngest to finish college and she is just finishing her associates. So do believe those points but seems kind of a crazy reason to end a marriage. Also said that this is not a ploy to force me into changing mind. That still loves me very much and hopes can be friends afterwards and have amicable divorce.