I came across with the next sentence:

```

    「そんな呼び方をして、馴れ馴れしくはありませんか？」
    「そんな、馴れ馴れしいだなんて」
    
```

Why is there a だ with a いadj? And what is the meaning or nuance of that だなんて?
CC BY-SA 4.0
2021-05-18T11:33:00.823
86683
2021-05-19T06:57:49.433
42280
question
grammar meaning nuances adjectives i-adjectives
What does だなんて mean?