Well, colour me interested. Extremely interested.

What Jackelope said. More!

It was the look that said Twilight was planning another of “those” experiments, the ones Rarity suspected that Twilight secretly enjoyed the most, the ones for which Twilight increasingly seemed to favour Rarity as a “test subject”.

: "Normally I'm the 'test subject' for Twilight's weird experiments (even if they usually only involves explosions and mustaches). Hopefully she would let me participate later. I mean, it's with Rarity..."

Well she couldn't say “no” to that now, could she?

Nope.

The moment I saw the picture on derpy I knew there would be a a story about this picture. Luckily I didn't miss it.
Looks good so far!
I'm curious what other things she will have to try out. (For science, of course.)

Oh this is HOT, I would LOVE to see what happens next to Rarity, maybe a portal into her mouth so she will be sucking other stallions off as others fuck her pussy and asshole, maybe even make it so she can be fucked by multi-cocks in the same hole but not be stretched out wide.

Holy shit another portal sex story i wish they have more of this.

Have myself been really interested in writing some thinking with portals stuff for a while now, really looking forward to this

For science

Love it!

More please?

Certainly a creative use of magic