A few weeks ago I saw my dad spank my brother: thread here www.mumsnet.com/Talk/am_i_being_unreasonable/1032986-To-be-absolutely-shocked-at-my-dad. I've just spoken to my sister who's just seen him slap my brother across the face for being argumentative. I'm now really shocked and worried about my brother and my dad. My dad was never violent to me or either of my 2 sisters but we are much older than DB. My sister said although he was arguing with my dad it certainly didn't warrant a slap across the face (if they are ever warranted iyswim). I'm seeing them both tomorrow so I was going to discuss it with them but I was wondering what you would do.