Normally it's the other way around, where it's like a younger brother lusting for his brother's wife or something, but it's kind of nice to see the opposite side sometimes.
And, well, "Cheating", but I still love me some NaPaTa releases.
So nice, I didn't undesrtand the cheating tag at first. Checked the description, now I get it, but I can't get myself to find the story something other than nice...