I think part of the problem with the tense in this story is that you changed it twice in the first paragraph. There's nothing wrong really with writing in the present tense, but you have to stay consistent. For example, "Kim accepted immediately" and "She approached Kim" should be "Kim accepts immediately" and "She approaches Kim".

Also, I'm not sure if Squunch mentioned this in his email, but be careful when you use pronouns that it's clear to whom you are referring. This gets tricky when the scene only involves two females. For example, you have Kim speaking, asking Monica to call an ambulance, and then you follow that with, "She sticks two fingers…" which to the reader would imply that action is carried out by Kim. I figured out through context that it was actually Monika, but you don't want there to be any ambiguity there.

I agree with the other two posters, though. It's pretty good, and I always welcome more non-con snuff on this board, and it looks like the stuff you like to write about perfectly aligns with my own kinks.