Dream about my crush getting married to someone. does this mean anything?

Not specifically: All of us frequently dream of failing at some task -- often an exam -- that we've already succeeded at in real life. Freud himself noted that we dream of our most prized successes as if they were failures, and could not answer why (if there is a "why"). I'll bet you're simply proud of the way that you feel. Wishing you both happiness, whether you end up together for the long term.