So all the loving that took place between Charles and Erik in First Class is still intact, regardless of how they feel about each other later! CB Ooooh my God yess!! Thank you so much for explaining for me!
Basically whats going to happen is First class and the 70s Part of DOFP will set up the new timeline and its why the decisions of young Eric and Charles are so important in this film. so neither parts in these 2 films will be erased and when its said apocalypse will be a First Class sequel which is hinted to be in the 80s, they just mean a continuation of the First Class arc. First Class > Days of future past > apocalypse