Humite-Ubie on DeviantArthttp://creativecommons.org/licenses/by-nc-nd/3.0/https://www.deviantart.com/humite-ubie/art/Commiss-Dancing-Through-Time-1-527183129Humite-Ubie
A commission for I am quite sure there is a bigger story behind this commission, here we see Celestia taking care of a baby Spike and years later dancing with a teenage Spike, probably in someone else's party.