My sister-in-law has been number one on my fantasy list since the day I met my wife. SIL is 4 years younger than my wife. She could be my wife’s twin. Only difference between the two is my SIL has a chest twice the size of my wife’s. Several years ago SIL was visiting and changing into bathing suit to use our hot tub. Didn’t close bedroom door completely. I got a great view of her naked. Instant erection. Wife knows I like her sister physically and he bi-curious side wants her too. Maybe………………