I imagine Celestia’s pussy is hot - literally. Like it burns the cock when you attempt to fuck the princess of sun.
Similarly with Luna, where instead of setting your weiner on fire after putting it into her vagina, it freezes.
Not my kink tho, but hey, that’s what comes in my dirty mind
Makes sense. You have to PREPARE yourself if you are granted the honor of bedding a Princess of Equestria.
And funnily enough, they’re technically the EASIEST to seduce. Twilight by herself is difficult enough, but she has five friends to back her up, with a variety of lived experiences. If you are lying, even if you just exaggerating, she will find out.
Cadence is literally impossible. And not just because she is fanatically loyal to her husband.