AGAIN AND AGAIN

How long can Victoria and Nichkhun can Ignore each other and keep on forgetting all happens between them two?how long will they keep their relationship before?  how can they forget that because of Career they manage to break up. 

Main Story : Nichkhun and Victoria has relationship before when they were just trainee, but because everyone knows that "NO IDOL TO IDOL" relationship (SM entertainment rules) they decided to end their relationship.  all over the years they tried to acted like they doesn't know each other. no one in 2pm and F(x) know's about their relationship.