favours

   an extramarital sexual relationship

   Granted by either sex to the other:

    The small luxuries of life that plenty of women were prepared to exchange their favours for. (G. Greene, 1978, and not of political allegiance)

    A fondness amounting to sexual mania for the favours of young men. (Sharpe, 1977)

   To force favours from is to rape:

    But even as he forced his favours from her... (Keneally, 1987 — or should it have been 'her favours'?)

   Favours may also be shared:

    And who does she pick to share her favours with? (Bogarde, 1981)