Just as my wife and I begin seriously discussing having a baby, my adult sister forces her way into our new home because of school. Living together would be manageable, but she seems attracted to me and uses every trick she can to seduce me. By getting me off every day, she sabotages our attempts to start a family. I firmly reject her at first, but gradually become drawn to how cute and sexy she is. Now, by the time I have baby-making sex with my wife, my semen is thin and nearly spent.