Boy!

boy

An expression said when one is excited, pleased, or pleasantly surprised. A lot of people sure came to the fundraiser, boy! Boy, that was a delicious birthday cake!

Boy!

and Boy, oh boy!
phr. a sentence opener expressing surprise or emphasis. (This is not a term of address and can be used with either sex, although it is quite informal.) Boy! Am I glad to see you, Molly!
References in classic literature ?
'Your hand, my boy! Why have I never heard until the day before yesterday of your suffering yourself to be cooped up in jail?
Think how great was his surprise when he saw that the donkey was weeping--weeping just like a boy!
You're a boy! What's the matter with you?" In teaching, the development of emotional intelligence in youngsters is an essential element of what we need to nurture and this should impact upon how we talk to boys and how we talk to girls.
'You've made a friend for life there boy! Old Pedro's never had so much fuss made of him.' The boy shrugs, drawing up his shoulders, a fluid gesture of defiance.