do any favours

not do somebody any favours

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