We are in a love triangle

I've had a lot of female partners in the past, but none of the relationships really went anywhere. Meanwhile my best friend since childhood was able to find the love of his life very early on. I am close to both of them, but I feel a DEEP physical attraction to his wife. I would like to have sex with her so badly, but I know what it would happen to our friendship if I ever acted on my desires. I wouldn't dare suggest a menage a trois, but I feel I must tell him how I feel about his wife. It's MUCH more than pure sex. It's like we're in a live triangle.