Time for the total weirdoes to come out. How about incest? I want to marry my brother, we are too old to have children, so why not? We are two consenting adults and we love each other, isn’t that the argument?
How about incest? Etc....
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Why should “what someone does in the privacy of the bedroom” be the determining factor? Why can’t a mother whose son moves in with her be her significant other for ‘entitlement to benefits’? Or two elderly sisters sharing a home, or two elderly brothers, or you name any combination of adults, or why stop at adults ......
What’s “too old to have children” have to do with it?
The claim is that “any two people who love each other should be allowed to marry”.
Once they start putting limitations on that, we’re back to the fact that standard heterosexual marriage has lots of limitations on it, and that one of the limitations is that there shall be exactly one man and exactly one woman.