Clearly  Twilight is declaring her desire to sire foals with Rarity.

Twilight is already talking about what to do after birth. She really gets into her fantasies and she likes to plan ahead.

That I most certainly can and do believe.

Now I’ve read some RariTwi (quite a bit in fact) and I can say those two can come up with some pretty “interesting” ideas together. Though Rarity’s face is bordering on ‘Not Sure if Want?’

Needs more staple-gun