All of the N's behaviors that didn't make sense then, make total sense now when they're combined together. The repetitive nature of these behaviors during my relationship with him also lead me to believe that the N has been cheating on me the whole time he was involved with me. The last affair that I found out about might not have been the first.
Triangulation is a manipulative technique where the toxic person such as a narcissist uses a third person to influence the relationship between you and him/her.
The act of disappearance, or discarding of the victim, is the hallmark of toxic relationships inflicted by narcissists. They can vanish and leave the victims confused and dazzled at what just happened.