JUX-491 Secretly fucking my best friend's wife while traveling

The Shiina couple had a good relationship when they first got married, but after a few years, they completely cooled off. My wife, Yuna, has had a boring daily life without married life for more than a year. At that time, my husband invited me to go on a hot spring trip for the first time in a long time. Yuna, who wants to improve her life, readily agrees. And on the day of the trip, Yuna arrived at the boarding house with faint expectations, but she did not realize that what her husband was thinking was bolder and more obscene than what she imagined.