I don't know if I would have been brave enough, but at least I would have a plan: i would told here, that she seems to be a interesting person and would have invited here to a coffee.
It may have been a combination of a thick sanitary pad and underwear giving a very visible panty line along with your want for it to be a nappy making it look that way.
I have wonderful Kids and they're keeping me with my vanilla wife.
She is not participating any of my kink's and I have many.
But since then its about 15 years ago I know what I would do if I would see someone else wearing a diaper.
Before I started wetting the bed I felt a bit guilty about wearing nappies but since I started to genuinely need them I really don't care anymore.
But i was so perplexed, that I just continued my drive home.
I should have left the motorway and asked him to go drink a coffee.