Smothered Under My Dirty Socks

I want to test out what this slave can treat and begin to throttle him under my dirty white socks. My big feet cover his mouth and nose pretty well, but he still attempts to cheat by breathing through the edge of his mouth! Obviously, I cant tolerate that - so I grab some duct tape and tape his mouth shut! Now that he can only breathe through his nose, its easy to smother him under my feet - and I can start to really test out his limits!