There is a true story where a couple just got married. Soon after marriage, the wife is diagnosed with certain illness by the doctor. To make it short, because of the illness, the wife is not allowed to have sexual intercourse. The wife, however, tells the husband if needed he can have sexual intercourse with other woman to meet his biological need.
In this particular case, if the husband has sexual intercourse with other woman, does he break the 3rd precept? Any source provided to back up the answer would be great.