Some sexual tales are too fantastic to be believable, but are nonetheless true. This is partly because of the various taboos surrounding sex and the way that, until recently, people were not comparing notes. Different cultures regard sexual acts very differently, and the more repressive social structures encourage secretive behaviors, often within families who keep their secrets secret and do not like to publicly make known what might go on.
Way back in my college years, when I was not quite 20, I was dating a girl from the year below me. Her family were a little protective of her, I thought for various reasons. They did not like her out late, although they were ok 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, Sharon, 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 about looked like putting a damper on much happening, but she was over one side of the room, not paying much attention, and I was on the sofa with Sharon snuggling up against me, and we were soon kissing.