"Once I had you completely and hopelessly addicted, letting you stroke your over-sized clit allowed me to extract some promises from you. That's how you ended up with those nice round breasts of yours. And how you ended up sucking and fucking my strap-on."
"But the really evil thing was spiking all your food and drink these last six months with ever increasing doses of viagra. Without it, you'll be pretty much impotant, especially after the last two weeks I've had you tied to the fucking machine, training your body not to get hard ever again."
You scream into the gag. You thrash at your restraints but to no avail.
"Now keep stroking. Stay on the edge while you can or I'll make you regret it."
Realising you have little choice, you comply, your whole body shaking with emotion.