Twilight Sparkle has been showing more and more “needy”. More than once, she was caught panting at the sight of stallions. As well as being a little, not so quiet, when she’s alone in her “studies.” So Princess Celestia comes up with a solution. First, she needs Spike to drink something.
“Sex” tab is there more because of the nudity in the story.

This is part of my 1K Challenge.
Would like to thank SonicBlitz18 for the idea.