All he had to do was say drinking blood from someone you love would end up killing them. That's it. They could still love each other and just make sure he doesn't drink his blood. There was no need for them to forget that night and push aside their feelings and act like normal FOR THE REST OF THEIR LIVES. WHY? (╯°Д °)╯╧╧
Even if they were to get together and try to resit him drinking his blood that would be hard because the more you are with them and love them the more you will crave their blood and it would eventually happen.
All he had to do was say drinking blood from someone you love would end up killing them. That's it. They could still love each other and just make sure he doesn't drink his blood. There was no need for them to forget that night and push aside their feelings and act like normal FOR THE REST OF THEIR LIVES. WHY?
(╯°Д °)╯╧╧