Should marriage be redefined again to include threesomes for bisexuals?

What about bisexuals' rights?

Marriage has few requirements:  gender, number, age, relationship.  If we eliminate the need for gender diversity to please people with same-sex attraction, should we also eliminate the number (two) to accommodate bisexuals?  Like the man in the Netherlands with two female partners.

If LGBT rights activists have the right to eliminate the gender requirement in marriage to accommodate people with same-sex attraction, do they also have the right to change the number limit to please people with both-gender attraction?  In other words, what about bisexuals’ rights?

Terence Jefrey at CNSNews asks, who do bisexuals have the “right” to marry?

Obama, we now know, believes homosexual men have a "right" to marry other men, and homosexual women have a "right" to marry other women. So, who does he believe bisexuals have a "right" to marry? 

In Obama's world, does a bisexual man have a "right" to enter into a bigamous union with one other man and one woman? Or can the state force him to limit his marriage to the union of just two people? 

And if that is the case, how would Obama, within his philosophy of government, justify prohibiting a bisexual from forming a tripartite marriage?

Do bisexuals have the same right to marry the ones they love that homosexuals have?