This is a really great story; but full of grammatical errors that ever so slightly make it difficult to follow along {e.g. "Rachel's thong digs for me..." followed by "... I'm dug out by the tongue like a cherry."  Is it "thong" or "tongue"?}, though nothing too bad.

Sitting on and squishing food items is a pretty common fetish, just look up cake sitting or Twinkies sitting.  There are a lot of videos of women sitting on pastries, as a girl's ass and a cake / pie / pastry are pretty much one in the same, or at least a delightful combination.  So that part of your story is probably relatable to most of us readers.

Chris being only 4 inches tall and serving Ivy's ass in fetish clips is a fantastic way of showcasing the size fetish aspect of their relationship.  Four inches is nice, yet three inches might be better for size comparison purposes {who better to sit on top a donut, a 4" tall person or a 3" tall one?}.  Just something to consider.

Really love that Ivy and Rachel are lesbians, and that Chris is nothing to them romantically.  Nice touch.

Hope to read more of this story; but please do a proof read and clean up the grammatical errors.