Creeping around with the sister-in-law
 

I have been married for close to nine years and we dated from some time before tying the knot. I have a great relationship with in laws especially my sister who I have know since she was a teenager. We have flirt off and on, which does not bother my wife because we are both her sister and I are know to be the bubbly flirtatious type, but recently it has become apparent that should I desire more she would be more than open. ... What should I tell my wife, say nothing and forget about it, or fuck her once and put it out of my mind?

fuck her and enjoy it while you can