Cousins: Not so cosy

Half your sibling, half your friend;
Half the emotions, half the feelings;
Everything's half, still it lasts;
The relation with cousin always survive;
Not too personal, not too formal;
Your cousin hurt you seldom;
We write on friends, write on siblings;
Cousin's love is never acknowledged.

They behave stupidly, They behave rudely;
Act annoyingly or look ghostly;
But when situations turn out wanting,
They rescue you mostly;
People visit others for advice,
While true adviser lies nearby;
Some work with heart, some with mind;
If involved both it turns out your cousin.