While in college, I would fantasize about my one roommate’s gf (who lived with us) walking in on me jerking off in my bedroom and immediately dropping to her knees and sucking my cock. One night while she had a friend over and everyone else in the house was out of town, I jokingly stepped across her while she was sitting in a chair in the living room. While I was essentially straddling her, she grabbed my cock through my incredibly thin shorts I was wearing. I’ve never gotten so hard so fast. After her friend went home, she insisted on sleeping in my bed with me. Once in bed, I was throbbing, and after giving me a few strokes she said she couldn't do anything about it without feeling guilty. Told her I had to get off, and asked if she wanted to watch. She followed me to my desk and watched over my shoulder as I stroked my cock to porn and watched me explode. To this day I regret not backing away from the desk more to give her a better view and see if she would have helped.