Phallic Friday - threesomes

I was excited to read this post today (http://www.news.com.au/lifestyle/rela...) on the news.com.au website.
It's about a family, in Texas, with 3 parents, expecting their 3rd child. It's a relationship between 2 women and 1 man, and they love their lifestyle. They claim that it allows them more time for themselves, each other and for friends/hobbies. They claim that they can parent and work, juggling the demands of life, much easier in a threesome than in a couple.
They also want marriage. They've been together for 5 years and would love to be married even thought it's not legal. 
And this is where I think marriage equality is missing the point. Same sex marriage, is fine, but it's really not enough. If you want to talk about equality, then it needs to be that marriage is available to any form of committed relationship. Yet, I know that's unlikely to happen because people baulk at same sex marriage, so I can only imagine how they'd react to multiple partners, or other forms of relationships. But I still think same-sex marriage should not be referred to as marriage equality because it's still leaving people without.
Having said that, this threesome relationship gives me hope for my new book, Team Player. My threesome is 2 men and 1 woman, but I'm glad that there are people living in multiple partner arrangements.