You’re no good for me
Baby you’re no good for me
You’re no good for me
But baby I want you, I want you

from Lana Del Rey – Diet Mountain Dew Lyrics on Rap Genius

Meaning

Women often seek the “bad boys” for their short term appeal.

Thus, Lana assumes this will be a short term fling because she has surrendered her power to his bravado, even though she knows it won’t last.
Here is an article explaining the psychology of it all.

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