It does fit, Crowley thinks distantly. Mostly his motivation is impatience, but it does fit. Under the night sky, in the light of stars he helped make once, long ago before things began. In the open air, in defiance of anyone who might be watching or judging. In London, where they've both rotated around each other for the past two hundred years. Longer. They've always been moving towards this.

The last second before their mouths meet seems to take an eternity, and for every bit of it Crowley is convinced something will interrupt, go wrong, change, explode, something. The shock of his mouth meeting Aziraphale's is more that is succeeds at all than from the feel of it.

The first kiss is little more than a touch and a breath, and then a pause.

Then he all but flings his arms around the angel, his mouth opening against Aziraphale's with an incoherent, needy noise as he pulls him as close as their corporeal forms will allow.