So there's this girl in my classroom, she is my crush (she has boyfriend), we aren't like best friends but we talk each other almost everyday. This is our last year in Highschool and at the end of the year we have like this graduation dance thing (I'm not sure how you guys call it in your country). She will enter with me and I'm planning to tell her my feelings (like alone somewhere during the party) but the problem is she told me if everything is going okay (probably will), her boyfriend is going to go to the party.

So I don't know what to do. Sincerely, she's reason why I am either happy or sad, she doesn't know anything of this. I know it was a dumb decision not to tell my feelings after 2 years.

But hey. Any advices are welcome.