The spider, since he did not get excited easily himself, manipulated him very precisely.
He seemed to pour all of his methodical nature into raptly observing what gave the king the most pleasure. Long fingers would stroke first slowly, then quickly, taking mental notes on every pant and twitch.
Each rhythm had its own tempo and sensation. The dancer seemed to dance across his skin.
He dragged others of his fingertips away from the what he was doing and back again. Asgore had never had anyone touch anywhere else during. Why had it never occurred to him, or them? The added sensation was amazing.
When he squeezed him, it was like he was a potter, molding clay on a spinning wheel, lovingly, carefully, slowly, into beautiful forms.
And when Asgore would convulse, almost violently, with pleasure, and cry out,
the slender hands would rest on him as if to say, shhhhhh, relax. Are you okay?
You are safe here in my hands, My Lord.
You are my very favorite project.
And when he was finally done, Asgore would always sit there, limp and gasping, with stars swirling before his eyes.
Others had roamed his body as a pre-planned tourist, who knew where they wanted to go and had a route planned out.
The Doctor explored him like a deserted island, new and strange.
To make the matter more interesting, he had multiple hands, so multiple bands of people to explore the new land.
Women had admired his shoulders and men had dived down the waterfall but Gaster would do things like observe with interest the angles at which his hip joints moved as he opened himself and kissed the inside of his thighs. And study his ankles to see how they compared to his little ones. All of his body was interesting to a man who had never had time to study anatomy in books, as he was so consumed with his other work.
And the fur. Oh how Gaster loved running his long fingers through every square inch of it. Toriel had her own, so it hadn't been as special to her. Not that he should be comparing, he reminded himself. All lovers were different. But Gaster was more different.
His already strong admiration for the huge chimera seemed to increase, too, like standing right under a building instead of seeing it a few blocks away.
And when they'd lie cradled together on the sofa, he almost had the thought that this was even more interesting to navigate that the flat bed. More of a challenge.
He just wished he could sleep cuddled up with him more. As it was, they snuck in naps and nighttime meetings as much as they could.