Part of the furniture

When we describe someone or something that's been in the same place for a very long time. You almost think that they're will be there forever. It's called "PART OF THE FURNITURE".

Image courtesy of http://www.bbc.co.uk

For examples
1. John has been the school caretaker for nearly twenty years. He's become a part of the furniture.
2. We came here so often, it's almost as if we are part of the furniture.
3. I joined the BBC in 1995, so I'm a part of the furniture at the BBC.