Will it work?

Marcus and Alicia have been best friends since kindergarten until present. They are currently in their senior year in high school. Marcus has always been one of those boys who loved to "play" with the hearts of girls. While on the other hand, Alicia, is the not-so-typical teenager with her tomboy-ish acts and the girl who always goes for the i-dont-care-look. They both weren't what would start as a friendzoned relationship because of how they both acted around each other, they were always so awkward but cute together. But suddenly Alicia realizes how much she feels for Marcus when she sees him making out with one of her best friends. Could it be too late to tell him how much she feels for him? Does he feel the same? What would happen to their friendship if he doesn't?