I think he's just bonded with you and trusts you first and foremost. The others will follow - boxers - or at least mine is quite long to trust new people. Especially if they are a different size from what he's used to seeing 
he doesn't yet know quite what to make of them. Mine used to bark like mad through the fence at the little girl next door because he'd never seen any small children, now he always goes to say hello.
I agree with Tootsie - the barking and tail wagging is play behaviour. Watch out for when they do start to play, boxers aren't aware of their strength and can get a bit carried away.
And he still barks at me if i put a hat on :lol: !
he doesn't yet know quite what to make of them. Mine used to bark like mad through the fence at the little girl next door because he'd never seen any small children, now he always goes to say hello. I agree with Tootsie - the barking and tail wagging is play behaviour. Watch out for when they do start to play, boxers aren't aware of their strength and can get a bit carried away.
And he still barks at me if i put a hat on :lol: !
