The Doctor is fascinated by this strange new species of ponies in this strange new world of Equestria. He wants to learn everything he can about them. You can't blame him for wanting to know how pegasus wings work, but you'd think someone his age would understand personal space.
Fortunately for him, Ditzy is very patient and understanding of his antics. Any other pegasus probably would have bucked him in the face for touching their wings without asking.

T for some suggestive humor. First-person, Ditzy's POV. Cover art is mine.
Not romance-heavy, but there's probably just enough to warrant the tag.