We need some help with a position that makes DH very tightly bound, but still leaves his ass accessible for reeming.

Ideally he'd be unable to roll left or right, sit up, or do much else besides take it up the ass. Would like his head free to sit on if possible, but that's about it.

Please help me take into account that he's 6'7" and 300 lbs and has 2 slipped discs in his back and bad knees.

I'm having a hard time thinking of a position that I could put him in that is as restrictive as he needs and I could still manuever him. Wrapping would work, but getting him onto the bed would not.

he's the type of sub who once in bondage immediately wants to get himself out and he's happiest when he's so tightly bound he can't possibly escape. Unlike me, who when I sub, pride myself on holding position and 'being good'.

Any ideas would be greatly appreciated, I'm stumped.