BDSM and a rapist are a dangerous combination. There's too much adrenaline, too many blurry lines (even with a contract), and a loss of control.

Not only is it dangerous for you, but both of you are increasing the danger for him. It's like the worst test ever with extremely low odds of success.

I noticed that you are very very sweet and seem to really want to defend this guy. And I think I detect a little anger and defiance because of the answers you really didn't want to hear.
I'm sorry about that.

I wish you all the best and hope that we are all very wrong.