Our almost 6 mo old male will not let anyone touch him except me, my husband and 2 kids. No one. We got him when he was 4 mos and think he only knew 2 adults and 12 dogs. He bites if anyone tries. Neither of our other GSDs ever acted like this, so we are unsure. Training with each person that comes over isn't going to happen (because they don't have time), but luckily our babysitter is willing. What do we do? He is learning to ignore people in public, as we take him EVERYWHERE we can.