fornication
noun
[ ˌfɔːnɪˈkeɪʃn ]
• sexual intercourse between people not married to each other.
• "laws forbidding adultery and fornication"
Similar:
extramarital sex,
extramarital relations,
adultery,
infidelity,
unfaithfulness,
cuckoldry,
sex,
sexual intercourse,
intercourse,
sexual relations,
coupling,
affair,
liaison,
hanky-panky,
bonking,
rumpy pumpy,
a bit on the side,
a bit of the other,
how's your father,
pata-pata,
carnal knowledge,
congress,
commerce,
