Due to popular demand, I wrote Cheese Sandwich's reply. :)

Dear Pinkie Pie,

You're the super-de-duper-iest of all the super-de-duper-iest-er! You're funner than fun, Miss Pinkie Pie! And thanks for the compliment, you flatterer. ;)

And, you know what, Pinkie? I've had the same exact feeling as the one that you described. Fluttery heart, red face, the whole kit and caboodle! You know when I sang you that song; y'know, about how you helped me be the super party pony I am?

Well, I kind of left out something. Something that I probably should've left in. It was really important, but I guess a little shyness from my colthood has stuck with me.

I've...

I've...

Um...

I've always had that weird feeling around you too, Pinkie Pie! From the first day I met you til' the day we partied together, and even now as I'm writing this, I've felt that way about you!

And I think...

I think...

I think that funny feeling, um, I'm pretty sure it's called...love!

...

And, um, thank you, Pinkie...for the offer to show me around Ponyville personally. That's the best offer I've had in...forever! I promise; cross my heart and hope to fly, that I'll come back to Ponyville. And when I do, be ready to give me that super special tour, okay? :D

Stay Cheesy!

-Cheese Sandwich :D

P.S. I can too! Party Planner Pal Pinkie Pie Party Planner Pal Pinkie Pie Party...Pinkie...Pal...Party... Er...

P.P.S. You don't have to remind me to eat cake, sister! Believe me, I eat bunches and bunches of it! Haha! :)

P.P.P.S. Thank you so much, Pinkie Pie! That's the best thing anypony has ever said to me in my whole life, I think! :)

P.P.P.P.S. Forget about you?! How could I ever forget about you in a million trillion years?! You're the most memorable pony ever! And I'm not joking at all, so don't think that! You really, truly are! I'd be a lucky stallion if I could be half as memorable as you are.