It happened a few weeks ago, but I’m still unable to fully move on. We were hanging out alone watching a movie when I became very aroused. He jokingly asked if he could give me head; I turned him down the first time, but he kept asking. Eventually, the horniness and the thought of it pushed me to accept.
I was so nervous and tense that I couldn't get hard at first, but once I closed my eyes and let go of my restraints, I finally got fully hard. I enjoyed it more than ever before and in the end was able to finish. Afterward, I felt hollow and a bit disgusted with myself, but I thought I got over it quickly. However, lately, whenever I'm masturbating and reaching that peak, my mind goes straight back to that moment. I don't understand why this is happening and I really hope someone can explain what’s going on, because I feel lost.