Fun to have by all even when in isolation
Reminds me of the 80's chicks-behind-bars flick
Lust For Freedom. The heroine, a wrongly convicted cop, is in isolation. Another inmate, a lifer, hears the heroine making noise. The lifer shouts out "Not pleasuring yourself, are you? If the warden catches you, she'll make you do it in front of her!"
That inspires a punishment for the one above, a much subtler punishment.
Grab her by all fours.
Haul her to another room.
Bind her spreadeagled to a bed.
Then put a fully charged vibrator between her tits.
Then turn the vibrator on.
Then enjoy the hours of pure pleasure as she screams and thrashes and curses in efforts to get the pulsating vibrator to her super horny, super turned-on crotch.
To add to her agony and humiliation, start a pool with the other guards on whether or not she will be able to get the vibrator to her clit before the battery runs out.