I don't know you, but I know all about you. I've known you since you entered her life. From the first date vibes, your habits, and to all the dirty details of your private "moments" and fights together, believe me, I've been through them. It's almost as if I was with you two through all those dates and text conversations.
You know about me too. I'm the one you asked for her clothes size, favorite color, and taste in food. You see my comments on couple photos you've posted, hear my name in her daily conversations, and we're even friends on social media. We were actually almost friends with each other, united in the shared love for her. You've responded to my stories joking asking to "return her." I have tagged you in memes of "third wheeling." To be honest, I sometimes got jealous of you. She put you first: she would spend more times with you, ditch our lunch dates occasionally, and would always talk about you. But even still, I liked that she had you in her life which made me like having you around.
Now, it's just awkward. You've unfriended her, blocked her, and removed her, but not me. I'm still screenshotting your Instagram stories and relaying it forward. I don't like you. I guess I stopped liking you ever since you started leaving her on "seen" and coming late to your dates. I didn't like how you got annoyed easily (something that seemed quite unlike you) and how you would prioritize your friends. But even then, she took your side, so I let it be because it really isn't my place. Since that's now over, I can be completely honest in showing my dislike of you.
You might think that I'm basing everything on her story, and you're right. But I've based my whole idea of you on her stories. That's why I thought so highly of you. You seemed so smart, so mature, so impressive. You felt like an adult and I truly respected you. For that, I have the right to be disappointed.
I can't hate you or be mad at you like her. We just don't share such emotions. But I feel betrayed by you. I thought of you as an ally. Actually, our whole friend group thought so. You cared for her as much as we did. We actually really liked you, because we saw how she would get when she was with you. It was a new side that she hasn't been with us. So when you broke her heart, you broke mine and those of all the people that care for her. You hurt all of us.
You need to realize that when someone comes in your life, they don't come alone. Instead, they come as an entirety, bringing their past, present, and future selves. With them, they bring the people that love/worry/care for them. I think you and I both forgot that. You forgot about the people she would bring and I took you in as only your present self.
So, if you see me on the streets, don't expect me to be civil with you. Or if I am, just know that I gave you a punch in my mind, not for me but for her. I hope that the people in your life would think the same.