A lady I know was 46 when she married a 23 year old man. The Catholic church wouldn't marry them. (She'd been divorced twice before.) So they were married in a very high church Episcopal ceremony. She is now 62, and they're still married. They adopted a boy, privately, without an agency. They are not what you would call good parents. But nobody interfered, seriously, with their marriage, or their adoption.
My one and only objection to gay marriage is that my sister has horrible taste in women. You should see the nut casses she takes up with. She stayed with the last one for almost 7 years. At least there wasn't any legal tie between them.
But I don't see why my sister shouldn't have the same right to marry losers that straight women do.