orgasm denial envy
A single slave in the facility is singled out and permitted to cum while all the other slaves are in complete orgasm denial. If s/he has been selected previously, the slave begs and pleads to not be chosen again. The chosen slave is fucked by machines, the PC, or someone else, or all of the above until they are sick of orgasms. An alternate choice is to have the denied slaves service the chosen one (PRAISE BE), which would build resentment. If the PC is feeling generous, they can elect to release the pent up slaves to gang-fuck the "lucky" one (re:bukkake). Alternatively, the PC can instead have a marathon of a session with the lucky one in the center of the facility while the others watch. Could go any which way, really. It's all about the haves and have-nots
Customer support service by UserEcho
interesting, but this depends on the test subjects having feelings towards each other. This seems impractical for a lab where you'll constantly be cycling in new test subjects.