In high school I had a cute female friend a couple of years younger than I. She was a petite brunette with C-cup tits and a soft pale skin. We'd hang out in her room after school every day, and developed this routine where I would give her a long massage while we listened to records.
After following this routine for many weeks, it got to the point where she would strip down to her white cotton panties, and I to my briefs. My favorite thing to do was sit behind her and cup her breasts, which I was brave enough to try and she free-spirited enough to allow. Needless to say, my cock was rock hard the entire time I was in her room. Unfortunately, she never seemed to look at the prominent tent in my underpants, which caused a gap in the waistband one could look down, if one wanted to.
She dated much older guys and it was understood that we were just friends. She never touched me, and the one time I tried to get her to massage me she stopped after a few minutes and said, 'I like it when you do me instead.' Whatever...I wasn't about to argue, as I had a good thing going as it was.
Eventually, I came up with a plan to get my rocks off. As she lay on her stomach, I straddled her, sitting on her rear as I massaged her back with lotion. As this involved long, deep strokes which I repeated for up to an hour (I wasn't in a hurry to stop and get dressed), I was afforded an opportunity.
One afternoon, as I massaged her back in the manner described above, I discreetly took out my cock, and with one hand rubbed it with some of the lotion as I massaged her with my free hand. I used slow strokes on my cock so as not to arouse suspicion. It didn't take long to squirt a heavy load all over her back (she stirred a bit when my legs involuntarily clenched her a bit too hard during my climax), which I then rubbed in with the lotion. All that cum turned white and creamy, and for a while I panicked that it wouldn't dissolve, or blend with the lotion, or evaporate, or something, so I kept adding more lotion until I was convinced she wouldn't figure out what I had done, and she never did. Even after I repeated this stunt several times after that.
One day I convinced myself she really liked me because she let me touch her so intimately and see her topless, so during one massage I tried to rub her pussy through her panties. She grabbed my hand and stopped me, saying 'No. We're just friends.' Oh, well!