This really embarrassing situation happened when i was 13. I had gone to a resort with my parents, aunt,uncle and two cousins (both female aged 15 and 18). I was left alone with my cousins when the adults had gone to visit some other relatives. So then i decided to take a shower. I took a shower for about 15 minutes then realized that my spare clothes were in the trunk of my car which my parents used to meet the relatives. I also forgot to take in a towel to dry off so i opened the door slightly and asked the younger cousin for a towel.But she said that the resort hadn't provided towels yet. I had also (foolishly) given my current set of clothes away for laundry. So there i was locked in a bathroom with no clothes and my cousins waiting outside. I waited in the bathroom for around 20 minutes then the elder cousin had to use the toilet so i had to come out - naked. I hesitated a little but then came out slowly making sure that i covered my privates completely. It was getting tough as i was getting hard down there. But i slowly crept into the sofa and used a magazine to cover up. My elder cousin then noticed my discomfort and told me " Its not like we don't know what you have down there. We've seen you naked before so why not just relax and let loose."
I was shy but eventually moved out my hands giving them a clear view of my penis. The 15 yr old cousin then started teasing me saying.."Aww look at all the hair! Tim has developed since we last saw him naked." This made me blush and hard and the same time.
I had to remain like this for another hour! It was really the most embarassing moment ever..