I ended up staying with my brother and his wife for my exams. However, I couldn't concentrate on my studies because I was so interested in my sexy sister-in-law. One day, I happened to see my sister-in-law's underwear and got excited, so I masturbated without thinking. What's more, my sister-in-law saw me doing that. The next day, I honestly consulted my sister-in-law. "I can't forget about my sister-in-law's underwear, so I can't concentrate on studying for the exam. Please help me." My sister-in-law was confused... But she put her hand on my hard, erect cock that didn't calm down and stroked it, saying, "Don't tell your brother." I ejaculated without a hitch, but instead of calming down, my erection got even harder, and I wanted my sister-in-law. I lost my mind and before I knew it, I had lost my virginity to my sister-in-law... I felt guilty, the pressure of having to do my best for the exam, and my erect cock that just wouldn't calm down. My sister-in-law was kindly there for me...