obligation chocolate; chocolate given by women to male colleagues, etc. out of obligation on Valentine's day
dishonesty; injustice; dishonor; dishonour; ingratitude
one's sister-in-law; stepsister (elder)
one's brother-in-law; stepbrother (elder)
father-in-law; foster father; stepfather
duty and humanity; (a sense of) moral obligation and humane feelings
mother-in-law; foster mother; stepmother
in all conscience; in honour; in duty bound
parent-in-law; parents-in-law
social relationship; friendship
perfunctory; going-through-the-motions-sort of (invitation, gift, etc.)
sexual intercourse permitted (by a woman) due to a sense of obligation (rather than desire)