not do (someone, something, or oneself) any favors

not do (someone, something, or oneself) any favors

To be problematic or detrimental to someone, something, or oneself. I knew that I had to get up at 4 AM today, and I didn't do myself any favors by staying up late last night. This divine chocolate cake certainly won't do your waistline any favors this holiday season.

See also: any, favor, not

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