Pani, some times the only intelligent conversations are those we have with ourselves! welcome to the club.....
Other than in the recent pictures for USFS D&W do not look like a couple at all. That image of him panting for breath on the ice and Meryl just standing there waiting for him to get up and hug her and the Olys is always in my mind. I am sure if they are asked whether they are in couple its beause that its the standard question for pairs/dance teams and also because they have been together for such a long time.
With T&S there is always a look, a nod of the head, hand holding and of course the hug. Their problem is they look so GOOD together thats why people always hope that they are/will be a couple.
I think in an interview Scott mentioned a jacket given to him by an ex girlfriend thats why people thought that Jessica and he were no longer together.