Much glory to you, good sir.

I’m pretty sure that you won’t mind me proving myself by doing having you my first customer, right?”

This sentence just reads...odd. Maybe it could be '..proving myself by having you as my first customer..' or something like that.

should have reminded her to mention that before we she left,

Who left? We or she? Might wanna pick one of the two to go with there.

I'm liking this so far.

Heh heh. This is why i need to write an Eris fic. She is so fucking sexy!

Maybe if she considered that, he wouldn’t be acting like a complete dick

Pronoun confusion. Or gender confusion. Or reader confusion. But definitely confusion.

You keep calling the mane six female.

For a second, Eris talking through the fourth wall confused me.

You switch everyone's genders and change their names... but you leave Applejack as Applejack.

3942479 Jack is a boys name.

Eris rang a bell over Butterscotch’s head, causing "her" to jolt. “That’s what I like to hear! I’m pretty sure that you won’t mind me proving myself by doing having you my first customer, right?”

I think you meant to put him there.

3942479 How about applejack could be used as a male or female name.