One morning my hot 15 year old sister came into my room crying. Dad had finally told her that her real parents were unknown - she was adopted. I was a good big brother so I put my arm around her and told her that it doesn't matter, that we'll always love her and that I thought she was the best sister in the world. Then, I dunno how it happened, but we kissed, and soon things got really passionate - clothes came off, and... we had the most amazing sex. Sadly, it didn't last. After I came, I found out the condon had split. She started crying again, and I got the shakes. We went downstairs, hand in hand, to break the news to dad that his adopted daughter was probably pregnant. I have never been less amused by the words "April Fools".