I understood the situations to be like this:
You have a boyfriend and you saw him kissing his ex-girlfriend, right? And you are asking what to do?
This is not about dealing with the past. This is very much the present
If your boyfriend kisses another girl, against the norms of your relationship (could be [polyamory] (https://steemit.com/advice/@nomad-magus/i-fancy-a-guy-that-i-met-have-i-stopped-loving-my-boyfriend-some-words-about-polyamory), then he clearly made the choice: "I don't want to be with you; I am choosing another one".
There's nothing to debate here. Say good-bye and move on with your life.
you are right.this is not about dealing with the past. i continue my present. forget my past. i visit your link & read the advice. its too good. now i am feeling better.
yes i told my past, i forget you & now i move on my life.