a grub or something that latches onto your cock, maybe like when you're swimming or just when you whip it out to take a piss in the woods and happen to be standing too close to a tree. at first it injects you with a bit of a numbing secretion so you don't feel it mouthing over your entire shaft until your dick is basically replaced with its body. you notice it only when you go to change your clothes, and holy fuck a big grub has its mouth on your entire cock! you don't know how to get it safely off bc it is on there, and you don't want to risk hurting yourself, and maybe for whatever reason you don't immediately go to the hospital. but then the numbing secretion wears off, and you can feel it - not just on you, but sucking on you, rhythmic motions that actually feel really fucking good.
grub latched on to your cock that keeps getting bigger every time you cum helplessly, and obviously you'll have to piss, too. grub that makes your bulge super obvious as it grows. grub that eventually has you confined to bed bc its gotten so big from your cum and piss and also it just feels so fucking good, in spite of the overstimulation, to be cumming pretty much constantly.
