Gf's sister

I watched a porn video where a girl received some huge facial and she looks a bit like one of my gf's older sisters (I can call her sister in law) which I'd like to fuck and cum on her pretty face like this. She is in her 40's and married, with 2 daughters. She told me that she never had the chance to try anal but she is willing to try it if she has the opportunity, so I was thinking that I could fuck her virgin ass and teach her some other naughty things which I like and which I did with many women, for example from ass to mouth and switching holes from ass to pussy, throatfucking, cum in her mouth and on her face. While talking with her she seemed open to all kind of things sexually. And she knows that I like to fuck women in the ass and that her little sister received also my cock in the ass. She also knows that other men used to fuck her little sister in the ass, too.
She is a tall sexy woman with a great desire for sex, but she confessed to me that her husband doesn't fuck her as much as she would love to.
I didn't have the chance to meet her more privately and to try to fuck her though we had some flirting exchanges. That's also because we meet very rare, because she is living with her family many many miles away. So I just jerked off while talking to her on internet, and watching her pics and thinking of her ass.