a stranger - Lying on your arm to block blood flow until it’s numb, then

Lying on your arm to block blood flow until it’s numb, then using that same limb to jerk off.

I blocked all the blood from my arm until it was numb, then I jerked off with it.

I lay on my arm until it went numb, then I used it to jerk off.

I blocked the blood flow from my arm, then I jerked off with that same numb limb.