Do somebody no favours - Idioms by The Free Dictionary
do somebody no favours
do (someone or oneself) no favors
1. To not be helpful to someone or something; to hinder or be detrinmental to someone or something. You do your kids no favors by catering to their every whim.
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.
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.