Instantly

The delivery page doesn't have tracking, just a countdown. The countdown started at six seconds, weirder and weirder this is getting (5). It seems to be working (4) as intended you think (3). Maybe it's still just a joke, wait why is your address on screen (2)? As the last seconds approach you notice what was a sunny day has become dark, not completely, but almost like you were suddenly put in shade. You go over and open the drapes for the window, and looking around the entire block is dark. Looking around, actually the whole city might be dark. Freaking out you run outside, whatever is doing this can't be natural and you're worried you might have caused it.

You run outside, and immediately look up, and to your dismay, or excitement, you see a giant horsecock a few hundred feet from the ground, beyond that you see it extending and connecting to what looks like the underside of a horse. You are the only person who would know otherwise, it in fact is attached to a giantess centaur shemale. You take in the sight, a penis large enough to probably plow deep into the earth, easily deep enough to dismantle a city, and huge balls to match. Though the balls seem to be swelling, it's happening fast now that you're noticing, if this woman needing to walk those things would quickly way her down and lift her from the ground. Her cock then jerks, and a few white drops as big as houses falls from the tip.

"Did she just cum?" You thought as the drops fall near you, though one is near enough that you get hit and covered by it. Immediately you feel weird, what you didn't know was there was a massive load of chems in that shot, probably more, all meant so you specifically could satisfy her growing cock. And it was growing fast.

The pre-chems worked into your skin, busting out your bust large enough to make you fall over and they held you up a good ten feet from the ground after they start to stabilize, but that's not the only change. After your front is settled next is your rear and hips which quickly tear off the remaining clothing. You are able to note that your ass is almost the exact same size as your boobs, and your hips flare out to take up about a whole street width. The last change is almost more major than the first two, in that your height increases, slow at first then boom, you're a few blocks long with proportional assets to before that change, which makes your hips stuck between two buildings ass up. It's almost like your body wants to be at the mercy of the centaur goddess.