My Secret Nighttime Experiment

I've been in a long-term relationship for years now, but lately I've found myself secretly exploring something new. Last night, after my partner fell asleep, I masturbated while imagining being tied up and helpless, unable to touch myself. It was intensely arousing as I felt my fingers slide over the rough surface of an imaginary gag inside my mouth, each movement causing me to moan quietly into it. My hips bucked harder against my hands as I imagined a stranger's rough touch on my body, pinning me down with their strength while I tried desperately but fruitlessly to free myself. The sensation was exhilarating and shameful all at once.