I agree whole heartedly with deux_anges; but as I do with some of your stories, breast expansion seems to take a third seat among the focus of the story... third to the narrative(good thing there, actually), and second to the sex. Good detail on the BE, not enough of it, though... both in instances of the breast expansion, and in that I just think they ought to get bigger, but then again, I'm a bit of a WOW sized breast fan. Some lactation would be nice(Did I say some? I meant OCEANS of it :P).
Now, the details got a bit confusing when the main character[of whom I don't recall his name being mentioned in the story; the coitee(I just know I spelled that wrong) never call him by name, and his narration is first person] escapes... particularly when he jumps in the blue liquid. Is he in a pool that is draining, or in more of a waterfall, with access to air? The things he thinks at the time would suggest that he could breath, but there was no confirmation in the description of his surroundings in that particular moment.
Finally, I really look forward to seeing(or should I say reading?) more of Angel... not enough elaboration on what is going on with her in this story, though that will probably be rectified in your next installment.