If the other person is willing to do a little more than just point and click, Moon+ Reader (no desktop version) can export and import your notes and highlights.
Their FAQ states that the built-in Backup & Restore functions (instructions in 3rd and last questions) can be applied to either the entire library, or any given single title.
Apparently there's
also a way to transfer notes from FBReader, but that's a lot more technically involved (and the comments have a caveat about the transferability of Google Play Books' notes/highlights to Google Drive, which may or may not apply in your case).
ETA: Lucidor which is available as a Firefox plugin is mentioned on its
Wikipedia page as specifically being able to export one's own notes and highlights to import to read with another person's copy of the book. It does not appear to exist in an Android version, though.
ETA 2: Here's a
Tech Republic blog article which specifically details Lucidor's highlight export/import functionality and how it can be used for sharing notes.