We Pranked Her Brother

A lot of you probably have a friend where there family becomes an extended family of yours right? That's how this is.
So I'm in a group with people that swap nudes of each other and or their significant other, my friend is in that group as well.
Well not too long ago, his sister started messaging me after my divorce and to my surprise, we started talking about sex. The group came up and she asked about joining.
I reluctantly explained that her brother and his wife were part of the group. One thing lead to another and she confessed she was always secretly attracted to her sister in law and wondered if I'd share some of the pics I had of her. I was reluctant but she bribed me with pics and vids of her own so I relented.
Turned on, she told me she was masturbating to them and even sent me vids to prove it, which in turn, turned me on. We all know we aren't in the best frame of mind when turned on...this is where the prank was born.
So we came up with the idea of cropping her face out of her nudes and having me send them to her brother as part of the group.
He loved them, so we continued this for months. He would cum to them, telling me how perfect the tits were and the things he'd like to do to them.
I would screenshot the conversation and send it to his sister, turning her on even more. She ended up actually joining the group and just never posting her face, or if she did, it was with a mask.
Watching those two talk and pass pics in the group was a huge turn on for me.
She isn't part of the group anymore and I never asked if she ever revealed who she was or if anything ever went further. I will say that I agree, her tits are fantastic and still have and "use" everything she sent to this day