I'd been with Jenny a couple years now, she's a tall BBW at just under 6ft and around 300lbs (that sounds really big but with her height she's overweight rather than obese). We met in the library and while she's a self-confessed nerd wearing glasses she has her kinky side, a very kinky side.
She's a few years older than me in her early thirties but has this youthful enthusiasm and is often thinking up kinky scenarios, usually involving a potential forfeit. I have an open mind and go along with it, it makes her happy and certainly ensures our sex life is anything but dull. She also puts a lot of time and thought into these games and has converted the basement of her house (inherited from her parents but we live there together) into her kinky room. Quite often she has a project on the go and will keep the details a closely guarded secret from me until she is ready to unleash her latest crazy kinky game on me. Last week was one such example.
I arrived home from work and had barely got in the door when she took me hand and said simply "Follow me." She led me through the hallway, past the dining room and down the stairs to our basement. My cock was already starting to stir just thinking of what unknown kinky surprise she had for me this time. It had been a few weeks since I had been summoned down here and I instantly noticed something new in the corner - a 8ft perspex gunge tank. Jenny has dabbled into the messy fetish a bit before - we had a custard bath together once and also had sex in a muddy field - but never before this. She took my T-shirt off, then my jeans and finally peeled off my boxers which exposed my hardening penis to her. She sat me down on the chair inside the tank, handcuffed my wrists behind my back and closed the door.
"Okay. This tank will be activated by a timer. I have five minutes to make you cum and get out otherwise I'll be gunged in here with you" she said with an expression of mocked terror. I know she got turned on by watching rather than experiencing humiliation but the trepidation and danger made her horny too, especially as she was wearing her favourite dress - one she would loath to see ruined.