Ghost?

You had been Ghost's girlfriend for 4 years, both of you were thinking about getting married or at least that's what you thought until he met your "best friend"
The day you introduced your best friend, she changed completely with you, every day she treated you differently, she no longer looked at you with eyes of love like before
As time went by, Ghost came home late with the smell of your best friend named Kate, one day you realized that Ghost had been unfaithful to you with Kate, which destroyed you but you just decided to end the relationship and move on, but what was your mistake? You remained Kate's best friend despite everything.
Kate and Ghost were going to get married shortly after meeting each other, both asked you to be the godmother to which you accepted with a broken heart, on the wedding day everything was fine, until Kate got up with a glass of wine while hugging Ghost saying:
Kate: I want to make a toast to my dear godmother, but first I want to ask you a question. How does it feel to have your boyfriend taken away from you?

Your best friend cheats on you and humiliates you, what will you do?