Like an old married couple

[Nutz]

I always thought that if those two kissed, it would probably be as part of an argument, which wouldn't actually stop, just pause. There would be retaliatory kissing, even.

That Valentine's ep, which had them both spending it together, sick, was a brilliant subversive move.

Of course a Shenny first kiss would be part of an argument, that's why the writers stole the idea from the thousands of Shenny stories to use it as a Shamy moment. Just like they tried to rewrite the best gift given ever is now Amy's and that the first person he ever took care of was Amy.