For years, Fluttershy and Rainbow Dash had feelings for each other. When they finally began a relationship everypony was happy for them, and when the break-up happened, it was unsure if this would destroy their friendship. But at the height of tension, a colt from their past comes back to haunt them and threatens to tear them apart forever

Mature for later and possibly third or fourth capters
co-author credit schiziod nightfall