Unable to stop herself she started the car and began the long drive back to the city.She began to compromise with herself. I'll just drive-by and take...a look at the place. No harm in that. The closer she got to the building, the more her heart began pounding, her hands were shaking gripping the wheel, her pussy was throbbing, this feeling the overcame her was new and never felt by her before. She felt, scared, but alive at the same time. As she came up to the building there was one street lamp. Squeezing my balls, teasing the tip of my glans, pulling hard on my shaft, everything just caused me to moan and give myself over to pleasure."Rich", she whispered in my ear, "turn round". I did as asked and faced the wall. I could feel the cool gel run down between my arse cheeks. I knew what was coming and pushed my backside towards her. "Oh look at you, you dirty slut" she laughed and pushed the first finger deep into my hole. "I think you can take at least another" and she proved. I like that. As you can imagine I was quite wet already. So I looked at her and asked if I could touch myself, to which she replied with just a quick nod. I put my hand down my towel and started touching myself while she was still squeezing and massaging my tits. For the first time she didn't follow my lead though. I asked her if she wanted to touch herself and she shook her head. I asked if she wanted to watch and she softly smiled and nodded. I continued fingering myself.And she finaly said. I must admit that two children of mine at your age could let yourselves be found it such a compromising position disappoints me!" Dad grinned. "I would have thought that you would have at least managed to keep it hidden for a lot longer - my sister and I never did get caught by our parents and I don't think your mother and her brother ever did either. That's right isn't it, pet?"Mum nodded and said, "Yes, we made sure that we were never found out, either." We're not angry at you. Both of us had.