It depends. Some novels for young adults have universal themes and engaging stories that can appeal to adults too. But not all might be of interest to them, depending on personal preferences and reading tastes.
In addition, different cultures also play a role. In some cultures, any form of sexually - themed stories, even in a relatively mild form as bedtime stories, may be considered inappropriate. So, it really varies from person to person and culture to culture.
There are various types like those with different absorbency levels. In some adult stories, the mention of adult diapers can be symbolic. It could represent a loss of independence or a new stage in life. For instance, a character who has had an accident and now has to rely on adult diapers may go through a journey of self - acceptance in the story.
In some stories, adult diapers can be part of a story about recovery. A person who is recovering from an illness or surgery may need to use them temporarily. By focusing on the progress of their recovery and how the diaper is just a temporary aid, it can be a positive narrative. For instance, as the character gets better, they need the diaper less and less, showing their journey towards full health.