Plugs that you push into the breasts or something that covers them. The breasts then would swell to the back up of milk.

The idea of having a sidequest sort of thing where you go about doing a long term series of experiments and sciency sexy time with the end goal of breaking a person's will (for a variety of reasons) or altering their mindset into accepting a new fetish or sensation they otherwise wouldn't enjoy, or make them orgasm from sensations outside sexual stimulus.

an example scenario for what I mean in terms of changing mindset / breaking willpower is:

Have a straight, male subject come in and then strap them into a long term holding cell. Your objective is to break them into enjoying anal, despite how fervently they're against the idea. You set them up with something to stimulate them anally and a device to pleasure their penis so as to gradually get their mind to attribute anal stimulation with regular pleasure. You set them up and they're held there like that for a set period of time (can be adjusted for gameplay convenience) and you check in on them every so often to see how they're doing, see how many times they've achieved orgasm, willpower, sensitivity, etc. You can also take the time to speak with them, offer some opportunities for humiliation or encouragement, depending on how sadistic you want to be.

Depending on their progress, you can add or modify the current devices offering the stimulation. For instance, you can enhance the anal stimulation to produce a more pleasurable sensation but keep the penile stimulation at the same level. OR, you can gradually reduce the penile stimulation.

After several sessions of this, eventually you'll set it up that all he has for pleasure is anal stimulus, but he's far enough along that he might just climax from anal alone.

Once he's achieved several orgasms from just anal stimulation, you can set him up in the main experiment area and have some additional fun with your subject and see just how much they enjoy anal now.

Depending on whether you humiliated them or encouraged them, they might take to the sensation of being brought to orgasm anally and it'd be less of a "mindbreak" and more of a "Mind opening" for them (happy end) and they enjoy anal now.

OR, if you were more sadistic and constantly antagonised and humiliated them during the process, they become resentful and hate the notion of being able to climax from anal stimulus, opening even more opportunity to antagonise and humiliate the poor guy. ALl the while they detest being given anal stimulus, even though their body craves more of it. They can either eventually break and give in to their new desires, or remain steadfast in their rejection despite how desperately they need their ass to be plowed.

Another option is tricking their mind into believing that they can't cum without anal stimulation, watching them try to masturbate and be unable to cum without having something in their rump, or being unable to cum unless all they had was anal stimulation.

An example scenario for climaxing from sensations outside sexual stimulus:

Have either gender individual in a similar predicament, only this time, your objective is to get them to cum through other stimulus not typically associated with sex. For instance, tickling (or tickling specific parts of the body)

for example, tickling the navel of a female while having her lady bits recieve proper stimulation so that eventually her mind attributes tickling with sexual stimulus until she can be brought to climax by tickling her navel alone.

Another example of this is fondling of the ears or other such sensual touching that doesn't involve direct sexual stimulation. Same rules as above, offer the sensation and give sexual stimulus until the subject associates the sensation with sex, then repeat until subject can orgasm by just that sensation alone.

TL;DR: give the ability to have a side quest (possibly with its own test chamber) to modify the behavior of a subject through mental conditioning to whatever the player desires, specifically: implanting them with a particular fetish or having their body react with sexual arousal (to the point of climax) from certain stimulus that isn't supposed to be sexual, or is otherwise not something that would arouse the subject to that extent (such as a straight male receiving anal). Also make it possible to do the short and fun way in the main lab for those short on time or who prefer a more hands on methodology.

I hope I explained this in a way that folks can understand.

Inflate a subjects body and/or belly using a hose. Could be liquid, air or forcefeeding

Read the title.

its optional

Some idea from the old game "corruption of champions" https://github.com/herp-a-derp/CoC-Alpha

Lact aid: stimulate lactation

Lust potion: get in rut

Ovi Elixir: accelerate to lay eggs (if possible!)

Succubi’s Delight: larger balls (thus more cum)

Can Rack2 have something like that? (functionally similar)

PS hope to have more chemicals on transformation either!

I very much enjoyed the "Allow infinite size mods" cheat in Rack 1, and would like to see it return in Rack 2 (even if like in Rack 1 it may end up causing glitches).

Magic is a type of science... Right?

Pig Hole = plug with the middle missing, so the person plugged can be fucked with the plug in. Both are size play, humiliation and denial things, obviously; Fleshlights anally could also tie into gender play.

When edging or denying a subject for an extended period of time , they should start to beg or plead automatically. If they're more dominant they might try and hide their desperation , if submissive it would be outright. 

Ruined orgasm should be a fetish (main , not hidden) sort of used as a punishment in terms with denial or edging as well.