His breath came in ragged puffs, as the pressure built inside his skin. The feeling was intensely powerful, and he was drowning in sensation. His body arched forward, pulling at the restraints that held his wrists and ankles to the dark warehouse wall.
His attention was caught by a glint of movement -- a hand with shiny red nails came to rest on the helium tank valve. As she turned it another twist, he felt the flow of gas increase...swelling his already hugely rounded body.