The World Federation One Stop Fiqh

Ruling 1647

If a fasting man in the month of Ramadan has sexual intercourse with his wife who is fasting, in the event that he had compelled his wife to do so, he must give kaffārah for invalidating his fast; and based on obligatory precaution, he must give kaffārah for invalidating his wife’s fast as well. If his wife consented to having sexual intercourse, one kaffārah becomes obligatory for each of them.