No he's not a rescue dog - he's from a breeder. Yes we do measure out his food first in a measuring beaker, and so did the breeder before, so maybe he is thinking the mugs of tea/coffee also hold his food (maybe also because he can't see whats in the mugs from down there he might assume his food is in there).

Think i'll just try and expose him to us drinking out of the mugs - and if he jumps up tell him firmly "no", gently push him away and ignore him/put him in another room - and hopefully this behaviour will calm down.