>>6398
>>5977
Kuribayashi Chris does some great work like this, when he wants to. Here's one of his relevant works translated.
http://g.e-hentai.org/g/761667/f82b66e9f4/
>>6433
>>6436
It's more on the "monster" side of fuckmonster, but as they said it could just be a big bubble of mutagen or contagious spunk that sloshes around.
I particularly like the details of the tissues and trash can covered with cum. It implies a slower, savored transformation that they might not have been fully expecting, and thus trying to clean it up before it got out of control.