Making an elaborate system might be more work than the dev team is willing to put in. But writing blurbs about consuming fluids through orifices is very doable. Imagine the Minotaur Cum Addiction from CoC. In fact, you wouldn't even need to write an entire TF (unless you wanted to), as the perk would be the primary way of checking.
It's not very elaborate per se. It wouldn't be very difficult, to, as Hanzo said, for sex to restore hp/energy (but it could perhaps be very overpowered).
- Whenever Steele has sex, fluids are stored in the ass, hips and tits.
- The bigger Steele's ass, hips and tits are, the more they can hold.
- Amount of fluids decreases with time. If Steele runs out of them he/she enters a weakened status.
This, well, the only problem is biologically speaking, would mean it'd be a goo girl only perk. And yeah, on one hand there could be goo girls that don't want to be 'Cumvores' (and vice-versa of course - there's something deliciously subby/kinky about being literally dependent on sexual fluids). If this is anything like the minotaur cum addiction, it'll have extreme withdrawal side-effects like loss in stats, and if deprived for too long, some sort of bad end or a scene where PC is admitted in the hospital and under treatment, with some cut in his/her credits (a similar scene is already ingame if your testicle size grows so large you cannot move, I believe).
So there's two ways this could be implemented.
1. As it has been suggested before, by a virus/parasite. Like a mimbrane/tailcunt/tailcock, or maybe a bit more like myrellion fungus except no external symptoms. This means anybody could possibly become infected (which then brings uncomfortable plotholes such as why, if it is technically an STD, that PC's NPC partners aren't infected too). Unless this was non-infectious in nature, at least not transmitted via sexual fluids. Then which would mean, PC must have been infected in some imaginative way indeed. However for this one, fluid storage in tits/ass should be biologically impossible for anybody but googirl TFs, so that idea would be dropped.
- I don't know about name. Simply Cumvore as suggested earlier?
- It'd be more like energy/hp regeneration via sexual fluid intake (really overpowered unless in moderation, but every parasite/disease so far has had its upsides and downsides, so wouldn't do to make this one only have downsides after all. Just following the pattern. Thanks for the idea Hanzo :3).
- And of course, non-goo means fluid storage won't be linked to ass/hips/tits size, but it could be still made variable. Like a mimbrane trust meter, maybe the virus/parasite develops over time (having somehow been implanted in the PC at a larval stage), so being able to store more and go for longer without having to sate his/her urges as it grows).
- Deprivation effects could include decreased intelligence/strength/aim/reflexes/willpower, higher lust gain over time and higher libido.
- Going for too long without it means a scene will proc where PC ends up in the hospital, and the parasite/infection is removed (for a price). Or, if the parasite is already in a much more advanced stage, removal could be impossible, and the hospital could only temporarily stop the side-effects by feeding you fluids (for a fee, and the addiction stays). Willingly removing the parasite could also be done, as long as the parasite is not in a too advanced stage of growth, by a medical facility or bot, like the V-Ko?
2. As Hanzo suggests, it could be a googirl-only TF. As in, only googirls with a certain googirl score or higher, will all be affected with this affliction.
- Could just stick with Cumvore. Or Gooey Cravings or some name that suggests it is race-specific, like how 'Nuki Nuts ain't Testical Cum Inflation xD
- Energy/hp regeneration via sexual fluid intake can still work here.
- Fluid storage, and how long PC can go without, can be dependent on hips/tits/ass size, but also the thickness rating?
- Deprivation effects, same.
- Going for too long without it means a scene will proc where PC ends up in the hospital. The hospital will only temporarily stop the side-effects by feeding you fluids (for a fee), and could, for a further price, subject you to a specialized custom TF medication designed only to remove goo girl features (replacing them perhaps with your birth type body features (your birth species is recorded in the save file), or perhaps simply human features. If you refuse the treatment, they will merely advise you to be more careful next time.
- And of course. Removal is easy. At any time, just become less of a goo-girl than the requirement score. Or maybe, simply the only requirement for it is having a goo body perhaps?
Sounds pretty viable to me. I personally can't decide between these two >_< what do you guys think?