With just two months until my wife's birth, my mother-in-law, Mayuka, came to Tokyo from her hometown to take care of her. Thanks to Mayuka, the atmosphere at home has lightened, but there is still tension between my wife and me. My wife found out that I had been secretly masturbating, and I was in the midst of being banned from masturbating. In the midst of all this, I couldn't resist the alluring Mayuka, and ended up sniffing her underwear while she was taking a bath. I was so obsessed with her underwear that I didn't even realize she had noticed...