part of the furniture

US /pɑːrt əv ðə ˈfɜːrnɪtʃər/
UK /pɑːrt əv ðə ˈfɜːrnɪtʃər/
"part of the furniture" picture
1.

家具の一部, おなじみの存在

a person or thing that has been in a place or situation for so long that they are considered a permanent, unremarkable, or indispensable feature of it

:
After working here for twenty years, John has become part of the furniture.
ここで20年間働いた後、ジョンは家具の一部になった。
The old clock in the corner has been there so long it's just part of the furniture.
隅にある古い時計は、あまりにも長い間そこにあったので、もはや家具の一部だ。