I had always admired my sister-in-law. She was maybe six or seven years older.
I had just turned 18 when she noticed me watching her in a halter and shorts; she had a great set of tits. I would try to time it so that I would walk past her in the hallway after she came out of the bathroom and try to 'accidentally' brush her boobs.
Finally, one time she grabbed me and spun me around so I was behind her. She grabbed both my hands and placed them firmly on her tits. 'You've been staring at me me for years; I know what you want, so I thought I'd give you a handful.' Oh, they were so soft but I was able to massage her hardening nipples.
I pressed against her ass, hoping she could feel my growing hardon while I fondled her. She noticed all right, and smiled, but she told me that this was as far as she would go, that I shouldn't get any more ideas, just enjoy the feeling.
I told her that since I had a handful, maybe she'd like a handful, too. 'You mean give you a hand? Like a hand job?' Then she said if I had the nerve to pull it out, she might do it. I whipped off my shorts as fast as I could; my dick stood straight out. 'Wow,' she muttered. I always was larger than my brother. We slipped into my empty bedroom and she stroked me, slowly, gently, playing with my head until I burst over and over into my wadded up shorts.
Then she just as quickly eased out of the door, winked at me, and disappeared down the hall.
She never mentioned it, but a couple of times later she must have noticed me sitting in the living room leering at her with a hardon under my shorts. She would smile, wink, and mouth the words 'No, no.'
Never again. Too bad. But a great memory.