Wow, this confused me. Kim is obsessed with visions of bondage and being bound. She puts on the ponygirl outfit and pulls the cart on her own. Okay, fine. Yet she found Jim disturbing because he becomes someone else when she's helpless. So, okay, fair enough, she likes bdsm but doesn't trust Jim as a Master.

So, logically, she accepts an invitation from Jim to an out-of-the-way place she can't escape from alone, and then walks around, alone and at his mercy, trying on bondage outfits, while she waits for him to show up?

No this is not logical. Something is very wrong here. She claims she's in control and trusting some "damned site", but this is Jim's retreat. Who else should we expect to show up?

From the editing viewpoint -- you need to go over this a few times and proofread. It looks like you've run a spellcheck, but homonyms like feat/feet, reins/reigns, and confusion of lose and loose, show that you haven't checked these things yourself yet.

When using lots of flashbacks for backstory as you do, remember that the flashbacks must be in the right tense -- not just past, but pluperfect. And similarly, when recounting the story itself, simple past is appropriate. You have them mixed up at times.

Try reading the story aloud and you'll hear the tense confusion. You may also hear overused words like "shuddered". Try it.

Keep up the good work!