Harem Tags

Having 2 wives is considered threesome. 

The following is needed for a series to be a harem in an anime, manga, light novel, or web novel series: At least 3 members of the opposite sex being interested in the lead character (be it love or lust) are needed though the more niche same-sex harems and mixed-sex marriage do exist. Now, whether or not those 3 members need to be living in the same house as the lead is debatable.

Polygamy is having multiple spouses. Having 2 spouses is bigamy. More specifically, having at least 2 wives is polygyny and at least 2 husbands is polyandry! Similarly, polyamory is the practice of being in an intimate relationship with at least 2 partners but there is a consent among the partners to do so. Polyamory is a common practice among the harems where they are not married! However, it can be argued that sometimes a harem has the guy married to the girls from a practical but not legal standpoint! 

Having 2 wives is considered polygamy. Polygamy is the highest state of enlightenment a harem protag can reach.  

I agree that 2 symbolizes a love triangle, only 3 can form a true harem  

I would admire that person if the one of the partner is a yandere 

personally i consider the harem genre not about the number of girls but if the main plot of the story revolves about  several females that want to have or simply have a relationship with the MC
so baka no test, whose relationship (with the classmates) never go further than handholding is a harem novel
while warlock of magus world with its two wives and several sex escapades is not 

I would say no, personally I don't think that it becomes a harem until there are at least 3. 2 would classify as a love triangle even if there is no conflict between them. 

/thread