Husband has sexual activity with other woman with the consent of wife 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.
It does not break the third precept if the husband has the wife's willful(not forced) consent. It's somewhat similar to kings having more than one queen. 

Having said that, there is no such thing as a "biological need" regarding sexual pleasures. Water is a biological need, air is a biological need, food is a biological need as you cannot survive without them. You do not need sex to live.