I have definitely found that with older women. Society has told them its dirty and to get that change of mindset is difficult.My wife of nearly 54 years wouldn't let me go down on her until we'd been married almost 18 years. After 36 years of 'Eating Out At The Y' she still wonders why she waited so long. Just so you know, I'm turning 78 the first of next month, and she is turning 77, 6 days later.
In my case my wife had never had anyone go down on her until we met by which time she was 54.