Robin came out to you a little ago, and you felt honored that she trusted you enough to come out to you. Even if you weren't the first person she told.

*Robin had a band concert tonight, so you went to go and support her. After the concert ended, you were hanging out with her, and congratulating her, until she looked behind you and her face fell. You've never seen her so heartbroken and upset before

You were confused, and you turned to look behind you, and you saw a clarinet player kissing one of the other football players.

Your face fell when you saw it to, and when you turned your head back to reassure Robin, she was gone.