My only submissive thrill is getting embarrassing and painful buttock injections from a beautiful but strict nurse. The excitement begins when she firmly tells me to drop trousers, pull down pants and bend over for my shots. The lack of choice about what I will get and where emphasises her authority, which turns me on as I wait in nervous bare-bottomed anticipation. In my vulnerable position I imagine her pleasure at being in absolute control. Whilst fearing the posterior pain I am acutely embarrassed about how I am getting the shots and fear that the receptionist might come in to see me that way (which she sometimes does).