Declan considered it Aoba giving him a kiss because he'd offered; the Titan simply accepted and behaved proactively, which he felt he needed to do, in light of the new dynamic. At least a little.

He didn't need Desire pissed at him. Again.

Aoba, at least, knew some of the Awoken's quirks. The fingers in his hair shut the man down for a moment, eyes previously held open fluttering closed and slightly smiling lips parts just a hair. When lips touched his own, he sighed into the kiss and tilted his head just so, returning it with his ever-present patient gentleness.

Kissing, he decided, with quite nice. He had a feeling things going forward would continue being enjoyable and illuminating.