Eric & Ernie, not celebrating same-sex union legislation.
It's not often I've had the opportunity to say this, but I kind of feel my university newspaper scooped The New Yorker. By about 20 years. Because that was where and when I first heard of the theory that Bert and Ernie were gay. Of course, the University of Sydney's Honi Soit continues to go under the radar, unlike The New Yorker.
Then, as now, it seems a little unfair to force Bert and Ernie out of the closet, especially if they were never in it. Of all the roommates who aren't actually gay (they share a room but not a bed, unlike Eric and Ernie above) Bert and Ernie are the best choice to depict two very good friends celebrating same-sex civil union. Two characters not just popular with children and their parents, but popular with children and their parents across the generations. And owned by a great big and historically litigious corporation. This'll be in the public eye and drawing the 'what about the children?' argument whether desired or relevant, or not.
Irrespective, it'll sell some issues - even if it doesn't quite 'sell' the 'issue'.