Cousins touched me when I was sleeping

I was visiting my cousins house. I was 16, and my cousins were a 13 year old girl and 10 year old boy. I'd had some wine and felt a little sleepy, and laid down on a sofa. The girl laid down in front of me, the boy behind me. I was only wearing a pair of nylon swimming bathers. I just started to doze off, when I felt a light touch on my stomach, and then the cord of my bathers was untied. I then felt the back of my bathers being pulled down, completely exposing my bottom. It was the boy having a look. The girl then moved to have a look too, but he pulled the garment back up. Then he leaned across, and I felt the front of my bathers being pulled outwards, and I could feel his breath on my stomach as he peered down the front of my bathers and had a good look look at my dick. He then left, and a few minutes later, the girl lightly brushed her hand across my chest to see if I was asleep. A minute or so later, she ran her hand across my stomach. With no response, she slid her fingers down under the waist band, until she felt my pubic hairs, then quickly removed her hand again. Then, she put her hand into my bathers and began playing with my dick. I got hard of course, but still pretended to be sleeping. She seemed to know what she was doing, and she stroked and tickled my knob until I started to ooze pre-cum. Finally I felt I was going to cum and began moaning. She didn't stop, and gave a few quick tugs around my knob, and I shot cum all over her hand. She quickly ran off as I pretended to wake up. She came back a minute later, drying her hands after a visit to the bathroom. I had to act all embarrassed about the mess I'd made, and said I must have had a wet dream. She just giggled. But from that day on, she would always smile very sexily whenever I visited.