I Want My Sister-In-Law!

I want my sister-in-law in the worst way. I married a much younger woman and we were already very involved by the time I met her family. My wife's sister is a couple years younger than my wife. Almost from the moment I met her, there was a little bit of chemistry there. Facially, she is prettier than my wife as well as more fun, outgoing, and flirty. Despite my wife's ample chest, her sister puts her to shame as her bosom is about the same size but perkier and much more on display (she loves to show off some serious cleavage in some serious push-up bras). Her sister is living with her baby's daddy; who's a decent enough guy, but still treats women like he's in the eighth grade. To make matters worse, I now know that her sister is an even more overtly sexual woman than my very-open-minded wife because she got busted cheating on her baby's daddy when he intercepted some very slutty texts she was sending to a big stud of a cop she was fooling around with regularly. She almost wouldn't give up the sex with the cop to stay with her man because she liked his nightstick so much. My wife also told me a few of the offhand comments her sister was throwing around about cheating with the cop and you could just tell she was getting off, not only on the sex, but also on the taboo and the sneaking around. We're both freaks, so I can just tell that her sister and I would be completely sexually compatible, even more so than my wife and I. I want her so bad that I can barely hold a conversation with her at family gatherings as I'm afraid my desire for her will spill out in obvious flirting. Every time I hug her hello and goodbye, I get excited. I want to make a pass at her in the worst way, and I know she's very sexy and not that into her man. I have so much to lose with my kids and my wife and my house, but I want her so bad! What if I did and she said no, and then went to my wife with it? What should I do?

— Ron, 37