You could say that hafital's Chase the Whiskey for hlh_shortcuts is a first time story, though I think it doesn't go much further than a kiss. So was carenejeans's Nothing But the Truth. Both of them drew on subtext and unexpressed feelings between Duncan and Methos before the stories began.
I haven't reread it yet, but I think Mackiedockie's story, 'Tis Nobler (in the Mind), is a first-time also. That one, I remember, struck me as an old school story, though I don't remember precisely why now. It seemed that the sex was much more detailed, for one thing.
I think people are still writing first-time, but writing it differently, with less or no justification and explanation of how the characters find themselves considering each other as sexual partners.