Sisters, sisters...

There were never such devoted sisters

Never had to have a chaperone "No, sir"
I'm there to keep my eye on her

Caring
Sharing
Every little thing that we are wearing

When a certain gentleman arrived from Rome

She wore the dress and I stayed home

All kinds of weather
We stick together
The same in the rain or sun
Two diff'rent faces
But in tight places
We think and we act as one

Those who've 
Seen us
Know that not a thing could come between us

Many men have tried to split us up but no one can
Lord help the mister 
Who comes between me and my sister
And Lord help the sister
Who comes between me and my man

"Sisters" by Berlin Irving, from the movie White Christmas.