You look at the bulging black veins in your dick and decide that it's not a concern. It didn't do anything else that night, why would it do anything now. Maybe it would disintegrate into the blood stream, or just disappear by some other method. You lie back on the bed and settle in, letting your erect dick remain in the air. Maybe you should take this day off, yeah. Just get some R&R.
As soon as the thought crosses your mind, you can feel your dick involuntarily pumping. You look down and you see the black veins pulsing as waves of pleasure shoot through your brain. You quietly moan, but then, feel an almost immediate sense of relief. You lie back down again, panting, hoping for it to stop but secretly wanting it to continue. The latex seems to sense this unconscious thought, and begins pumping your dick again. Your back arcs, and you begin to will it to stop again, and it does. You spend a while afterwards, examining your corrupted phallus and trying to work out what the latex can do. Eventually, the thought of masturbation crosses your mind, and the veins begin to pulse again. However, you're prepared this time, and you quickly push down your horny thoughts, causing the pulsing to recede. Intrigued, you wonder if you can... will yourself to cum, without pleasure or without stroking your dick. You focus as hard as possible, and within a few seconds, sticky globs of jet black cum squirt out of the top of your dick and run down to your balls. You whimper slightly at the sight of the alien seed, but then you get a devilish idea. Maybe... the latex can change features. You decide to start small. "I'll just make my dick latex." You think to yourself. "And then once I've had my fun, I'll force it back into my balls. Easy as that." The plan goes without a hitch, as the rubbery symbiote wraps around your dick and balls, sending wave after wave of dopamine to your brain, and converting it to the same shiny, jet black material as the symbiote. With every wave of pleasure, you don't notice the few pellets of latex working their way through your arteries up to your brain, and by the time your cock is transformed, the seeds are already there.
For the next few hours, you make edit after edit to your body. First, you change the very nature of your human phallus, elongating its shaft, enlarging the balls, and gaining a flared tip. You decide that, next, the best possible course of action is to get some breasts so you can give yourself a titfuck. As soon as the thought crosses your mind, your massive horse cock starts pulsing and you spray liquid latex all over yourself and all over your chest. You chuckle weakly as the latex on your bare chest balloons into a new pair of double Ds. How you plan to cover them is an afterthought in your pleasure wracked mind as you coo gently and play with your assets. With your mind so corrupted, the symbiote no longer follows your orders, as you feel the largest orgasm you've ever had reaching your tip.
Eventually, jet black cum explodes out. Wave after wave after wave completely coats you with no end in sight. You sputter and gurgle as mountains of the stuff build up on your face, and it pushes down into your body whenever you open your mouth to gasp. The latex sloshes around, shooting down your body and pulling your legs in. You feel tentacles milk your prostate, and strands of rogue symbiote pull your pulsing, sputtering dick up against your body. Then, everything hardens. You can't move. You can't struggle. You can breathe again, as the latex has reached your lungs, assimilating the organic tissue into it. You remain there for days, maybe weeks, breathing silently. The panic recedes as you realize how little you can do. One day, after ages of attempting to reject the symbiote, you give up. Your struggles, which had transitioned to mental, cease. And then, you could hear some crackling, like someone crumbling up charcoal. Pieces of dried, dead latex fall on you, and you realize this is your chance. You gently push on the latex, and it gives way. Blinking into the bright sunlight you had been denied, you look about the room. It's the same as you left it, for sure. However, as soon as you catch a glimpse in the mirror, you obviously aren't.
Not only have you grown inexplicably taller and retained the previous assets you gained during cocooning, your entire body is far more feminine than it once was. In fact, your entire body is coated in a layer of smooth black latex. A few tugs show that it's not just a layer, it's your entire skin. If you cut your arm off, you'd probably be made of jet black latex down to the bone. And your face. Your face is no longer human. It's been replaced by some creepy grafted on gas mask, which merges seamlessly with your head. In addition, flowing nylon hairs hang down from the back of your head, jet black to match the rest of your body.
But are you terrified of the changes? No. You own this symbiote. This symbiote gave you a gift at your command. You grip your horse cock with both hands and begin to furiously masturbate, eventually covering the mirror in a sinful layer of jet black latex. It quickly hardens and everything, including the mirror, crumble to dust at your feet. If you could smirk, you'd be doing it right now, because your greatest dreams have been realized. Well, not in the way you wanted, but you know you have power. You ARE the Queen of Latex. The symbiotes tried to corrupt you and fail, and now you will build your own empire free of their will.
Only question is, what should you do first.