mi hijo
Two boys? You could say ellos, which means they.
You can say "¿eres un niño?"
Good boy = Chico bueno
papa
"amante"
you say it like this: clease boa
Niño guapo
Mal muchacho.
Niño chicita
Venga, chico.
no se que seria sin ti niñito
depends on the age of the boy. if he is really young, a child, you'd say: el niño con ojos azules. If he were older, you would say: el chico con ojos azules.