My freshman year of college I [F] used to blow my roommate's boyfriend when she left for class.
I was living in the dorms and had an assigned roommate named Cass. I was a bit nerdy and introverted while she was very outgoing and pretty. She was dating this super hot Asian guy named Lee and he would spend the night often. She had early classes and Lee and I didn't so she'd leave him sleeping in her bed.
One morning he woke up and was getting ready to leave and I noticed he had a morning wood. I jokingly said Cass must not be doing her job and asked if I needed to help him out. He said sure and took out his dick. It was bigger than I expected (the stereotype about Asian guys was not true, his had a good length and was super thick), so before I could think about it more I got on my knees and started sucking. I wasn't very experienced but I must have been better than Cass because he came in about 30 seconds and told me it was the best blowjob he'd had.
From that point on every morning that he stayed over and Cass left for class early I'd offer Lee a blowjob and he'd take me up on it. I never got naked, I would just be in my PJs or dressed for class. He never touched me other than to grab my head or feel my tits depending on if he was standing or sitting on the bed. This went on for the rest of the semester, and I sucked him probably 40ish times I think. I really enjoyed it, partially because he was hot and I liked his dick but also because of how slutty it was.
The next semester she joined a sorority and moved out and I only ever saw them in passing on campus. I think they were still dating but I don't know for sure. It was my first super slutty thing I did and helped give me the confidence to be more open with things.