It's Spike's third birthday in Ponyville, there's less damage than last year and all his friends are struggling to remember the night beforehand. Rarity, having taken Spike on a date goes to talk to Twilight about taking her relationship with Spike a step further.

But what does this mean, and is it even a good idea?
(A different take on the relationship between Rarity and Spike)

Rated Teen for themes and implied things.

Note: Image doesn't really relate, but I couldn't find one that did.