Odd things sometimes go on behind closed doors in families.
Way back in my college years, when I was not quite twenty, I was dating a girl from the year below me. Her family seemed protective of her, I thought. They did not like her out late, although they were okay with me bringing her home and then hanging out with her in the house. There was a back room which was relatively private, but we were still chaperoned by the girl's grandmother. I thought this a bit strange but consistent with her parents being over-protective.
Although a bit odd, this all made the girl, Miriam, even more, interesting to me and I guessed that she was probably a virgin. I was interested in popping her cherry - apart from introducing her to the wonders of her first cock, she would also be my first virgin.
Of course, having the grandmother in the room meant that I didn't expect much to happen, but she was over one side of the room, not paying much attention, and I was on the sofa with Miriam snuggling up against me, and we were soon kissing.
I had an eye on her grandmother, trying to weigh up whether she thought this was okay - I was a bit worried about going too far, but granny was not interested, it seemed. I thought perhaps she was asleep, or possibly her eyesight and hearing were not so good.
I took my lead from Miriam and reasoned that if she was okay with it, then I shouldn't worry about grandma, but I tried to keep quiet so that she would not take too much notice - or wake up if she was actually asleep.
So the kissing got more serious with tongues involved and my hand slipped inside her clothes to fondle her young breasts. When my fingers tweaked a nipple, she moaned a bit, but nothing from her grandma - so I just shut grandma out of my mind and concentrated on Miriam. My hands got more active, but Miriam responded as I would hope she would; keen eager and gasping when my finger slipped over her quite moist clitty.
Her hands had been at work too and, with a little help from myself, she had freed my cock from my trousers and had gotten it to a fine state of erection. I had completely forgotten about her grandmother and was concentrating on licking and sucking Miriam's nipples, encouraged by her hand around my cock.