do (someone or oneself) no favors

1. To not be helpful to someone or something; to hinder or be detrimental to someone or something. You do your kids no favors by catering to their every whim. You do yourself no favors when you try to push through your injuries. They need time to heal! There is absolutely a segment of video game enthusiasts who create a hostile and toxic environment online, but you do the community no favors when you dismiss the whole thing as "toxic."

2. To act in a way that reflects negatively on oneself. Just stop talking—you're doing yourself no favors by babbling to the CEO. All this negative press will certainly do us no favors! No, hold off—you'd do yourself no favors to respond when you're this angry.

do somebody no ˈfavours

not do somebody any ˈfavours

do something that is not helpful to somebody or that gives a bad impression of them: You’re not doing yourself any favours, working for nothing. ♢ The orchestra did Beethoven no favours.