Twilight Sparkle
The quite pedagogical Twi
Tried to use science on a guy
She wished biology,
Went with psychology,
Then all he could do was cry

Pinkie Pie

An orgy is like a party

And Pinkie can party hearty

She will gobble and ride

And take it inside

And all of these favors are free.

Applejack

She can buck the fruit from the trees

And suck a stallion to his knees

Very dainty and clean,

Always pristine

A country lass, eager to please.

Rainbow Dash

She's cooler by twenty percent

She has quite the sexual bent

The swift acrobat

Drains in ten seconds flat

With a temper quite prurient.

Rarity

There was a mare named Rarity

Who had a bit of vanity

A sweet little miss

A bit of a priss

But her bed was a place of polyandry.

Fluttershy

Shy and the color of butter

And apt to speak in a stutter

She's a secretive slut

With a mile-wide butt

Which makes her a capable rutter.

Princess Celestia

The greatest of any suns

Are the ones impressed on her buns

With a shimmy and shake

She makes a 'fleshquake'

And the sight of it always stuns.

Princess Luna

Moving her moon across the skies

She captures all the eyes

So full and so round

But glories truly abound

The greatest between her thighs.

Discord
A man, too, can have a monster ass
And also show off lots of sass.
Dressed like a maid,
Looking to get laid
And when thrusting he wobbles that mass.

Author's Note

Everyone knows what a limerick is.