The idea came while reading about the child crusades and thinking about how the "age of consent" concept has been wildly different over the ages.
So:
Nicky died young and therefore has not aged at all over the centuries.
-he died between 16 and 18 years old, any younger would make me very uncomfortable.
- he is as old or older then Joe in years lived
-when they start dating the fact that they are both men is more of a problem then the "age gap". This changes over the years.
Bonus: -booker having a really hard time with seeing Nicky as older then him
- Nicky being frustrated with modern times seeing him as a child