My wife does things with my brother that she doesn't do with me but that's because he likes things that I don't like. An example is he spanks and whips her. While I'm all for a bit of mild spanking I don't want to inflict serious pain on her.
As far as I'm concerned if that's what she wants she's welcome to it but not from me.
As far as I'm concerned if that's what she wants she's welcome to it but not from me.