待你长发及腰烧掉

Wait until your hair grows long enough to touch your waist then burn it off. There might be different layers of implied meaning behind these few simple words: either being tired of oneself and desiring change so drastically like burning long hair off after reaching waist-level, or this could refer to waiting for someone (with deep emotion), hoping this someone can realize something important just as they wait and make preparations (for marriage), but end up with extreme despair if disappointed and hence choose this dramatic action.