I work for an IT company and live apart from my wife. Because of her job, my wife often goes on long business trips, and when she comes home every once in a while, she wants to vent her frustrations, which makes me feel more and more stressed and sexually aroused. I have a good friend, my sister-in-law, Sumire, who often comes to my house when my wife isn't there. One day, while we were having a drink as usual and chatting, Sumire kissed me. Then, with a mischievous look on her face, she whispered to me, "This will continue if you can abstain from sex for a month..."