Idiom
not do someone any favours(not) do (someone) any favours
British, American & Australian, American to do something that is likely to have a bad effect on you or on another person.You're not well, and you're not doing yourself any favours by taking on extra work.
(often reflexive)
The government isn't doing the families of the victims any favor by hiding the truth about what really happened.
(usually in continuous tenses; often +
by + doing something)