Let me explain it to you. "Marriage" needs a man and woman or there is no "marriage" possible. Living with someone isn't 'marriage" and having sex isn't "marriage," but having the remotest possibility of begetting siblings and becoming parents (biologically), and therefore be either a mother or father --- TOGETHER --- that is "marriage."
Homosexuals will do whatever they wish; however, it isn't for me to reward their values with wrongly applied terms in order to sooth their "feelings." Let them call it something else; however, I will never consider them a "married" couple. I'll continue to call it by the old fashion term, "SIN."
Let me explain it to you. Marriage
by Little Nipper's definition needs a man and woman or there is no "marriage" possible. You derive this, I think, from what you infer from Jesus's pronouncement regarding the custom of men putting away their wives, and other Scriptural passages discussing behavior within marriage.
You have a right to hold that opinion. You have a right to state it publicly. But it is not the only possible definition. Mine: the relationship entered into by two people undertaking a formal vow that they will henceforth be each other's spouse, holding the other's needs, wants, and happiness as crucial to their own, and eschewing any possibility of the same relation with another while both live. Put more simply, saying: "You alone are the person I want to live with and love for the rest of our days, and I promise to do so with you."
One cannot impose one's own definitions on everything. (I know there are a couple of people here who would have issues with mine, even ignoring the fact that it allows for gay (and underage) marriages.) There are people on this board who would regard neither you nor me as "really Christian" -- though due to the rules they need to avoid saying so on this board. What matters to God is where our commitment is, not what someone else has chosen for an exclusory definition. And that's true both for "Christian" and for "marriage."
Added in edit: Oh, by the way... The word for what a father begets and a mother bears could be "progeny," "offspring," or simply "children" -- who would then be "siblings" -- brothers and/or sisters -- of each other. If your sex life involves {u]begetting siblings[/u], then the proper term to describe it would be one that the board's censoring software would instruct me to wash my mouth out instead of letting through.
And, as half of a very meaningful, God-blest marriage that did not result in children of our bodies but has nonetheless done a great deal of good for children abused or neglected by other, fertile types, I do want to stress that this "marriage equals children" crap is precisely that, and that by the very words of Scripture. Look at Rachel before Joseph's birth, Hannah Samuel's mother before his, Zecharias and Elizabeth expecting to die barren, Mary and Joseph themselves.