In Tolkien's legendarium he was very clear that there were three unions of elves and men. Which were those of:
- Beren and Lúthien
- Tuor and Idril
- Aragorn and Arwen
Tolkien also describes at least two other potential/actual relationships between elves and men.
- Túrin and Finduilas
- Imrazôr and Mithrellas
The union of Imrazôr and Mithrellas, ultimately led to the birth of Imrahil, the Prince of Dol Amroth, who was an important figure at the end of the third age.
Did Tolkien ever explain or discuss these other unions between men and elves and the inconsistency this causes with the statement that there were only three unions?