first name basis

Ben and I are on a first name basis.

For so many years, he was Sir Benjamin Moore to me, but now that we have gotten to know each other really well, he said. “please, call me Ben.”

Is there anyone in your world that you now call on a first name basis. I can think of a few others, like “Kate” – “Ralph” and “Oscar.”

You can call me “Patricia” just never “Pat!”