Smugly smiling down at her friend, Sektiss brushed the sweat streaked mane from Scarlett’s face. “This would make a great shitty fanfiction for us to read…”

Some well-executed self-referential humor right there

Oh? An Anthro mare is able to accommodate a 12 inch penis? A human woman's vagina is only four inches deep before stretching, and a real life 1600 pound mare can barely handle fourteen inches, but that's fine.

I understand that these characters are already hypersexualized, but I kind of assumed that a story calling out other stories for unrealistic body proportions would be a little more realistic itself, or at least more self-aware.

I mean, I liked it, but
>thick as a soda can
marks bingo card

Woefully unaware of her partner’s gut rapidly expanding gut,

Too many guts

“What? Giant tits?” the changeling asked, raising an eyebrow. Slowly, her rack returned to its normal size.

“Regular tits are just fine,” she groused, snorting in consternation.

“Yeah, but what about other big things like…” Sektiss purred.

Before Scarlett could say anything, something thick and weighty rested against her tush. Facing away from Sektiss, she had no way of knowing what sort of trickery her friend was up to. Steadily, she moved one hand behind herself, allowing her fingers to graze the vascular surface of what could only be a…

“Horse cock…” the changeling breathed in the Scarlett’s’ ear, causing the girl to shiver. Pressing her chest, and newly formed appendage to the pegasus’ back, she giggled. Yes, being able to alter one’s anatomy at will didhave its perks; although she preferred using it to better service a juicy marecock, or two, or a jester’s dozen.

Giant tits are the best for us stallions, and giant cocks are the best for us mares.