Artificial intelligent assistant

back-scratching

ˈback-ˌscratching, vbl. n. colloq.
  [f. back- A. 1 + scratching vbl. n., in allusion to the saying, ‘You scratch my back, and I'll scratch yours’.]
  The performance of mutual services; always with the suggestion of doubt as to the legitimacy of the transactions. So ˈback-ˌscratcher.
  (See also back-scratcher, scratching, s.v. back- A. 1.)

1897 Daily News 9 Jan. 4/7 Does it not rather partake of the ethics of the back-scratcher and the log-roller? 1924 P. C. Macfarlane Tongues of Flame xxv. 223 ‘That is the modern method of bribery, you know—back-scratching,’ she frowned savagely. ‘{oqq}We've scratched your back; now you scratch ours.{cqq} That's the system.’ 1933 Punch 24 May 567/1 Mr. Hugh Walpole made the startling suggestion that contemporary criticism occasionally showed symptoms of degenerating into mutual back-scratching.

Oxford English Dictionary

yu7NTAkq2jTfdvEzudIdQgChiKuccveC cf6eda867972dcc5991c71175404411c