Is there a reason a dog would nibble a nose or ear? Or is my dog just a silly goose trying to show affection?

postmaster Smiling Dogs

Yep it’s just your dog being silly! 

It could have started off as mouthing or as a grooming behaviour, but your dog probably realized that it made you laugh/squee/make other funny noises so now he does it often. Dogs are the best, really. -C