It was a Friday evening and I was at home with my wife and her niece Olivia (my sister-in-laws daughter). Olivia was celebrating her 20th birthday and had called round for a drink with us.
Until now, nothing had ever happened between myself and Olivia, but whenever she would be about the house, she always made it quite obvious that she having a good stare at the bulge between my legs.
Anyway, as the night went by, my wife decided to take a bath before she went to bed and off she went. I remained in the living room with Olivia and we were chatting away when she got up and sat down beside me.
Within a few minutes, she was lying down with her legs thrown over the side of the couch and her head resting on my thighs. She had never before come as close to me as she was now, so while I was a bit surprised, I could also feel myself getting turned on and I felt my erection getting bigger inside my jeans as if it was about to burst through my zip and pop out.
It did not take too long before Olivia noticed that I was having an erection and I could see that she kept glancing at it. I was somewhat embarrassed but I could not help becoming more and more aroused knowing that Olivia could see how turned on I was.
About ten minutes later, we both heard my wife coming out of the bathroom, having had her shower and getting into bed. It was then that Olivia made her first move. She grabbed me between the legs and squeezed, laughing as she did so.
I sort of half tried to stop her by holding her arm and I asked what she was doing but to no avail. She replied that she was having some fun and grabbed at me again, but this time, she gave me more of a grope than a squeeze, as if she was trying to feel the shape of my cock as it hardened inside my jeans. By now, any chance of resisting her advances had gone completely.