Girlfriend's Sister

When I was in high school, I stayed the night at this girlfriends house and she only gave me handjobs. In the morning, before I could finish, she told me to go home. When I was in walking out the door, her sister stopped me and noticed my massive boner and gave me the best fucking of my life and whenever I saw her sister, she made sure to at least give me a blowjob for the next fee years.