After not seeing Twilight Sparkle for years, Princess Celestia is surprised when Twilight shows up at the castle, needing a foalsitter for the daughter Celestia never knew she had. Princess Celestia agrees to foalsit for the young filly on short notice with deeper motives than a simple foalsitting job. The little filly is far from normal and the more Celestia learns about her and Twilight, the more she wishes she hadn't.

Celestia is determined to find out the truth about this young filly. But will she like what she finds?

Sex tag for the mention of sex but there is no sex.
Source for picture.