Clyde has been terrified from the moment he saw Mary Lynn, a fear which doubled until his moron of a wife became a goddess in her own right. He's not shocked when Amber drops him down her panties, as she had always preferred receiving oral sex to penetration. Clyde had stopped performing as often as Amber grew more distant (and as she let her pubes turn into a wild bush), but he hadn't forgotten how to do it.
So, much as he resented his wife in general, he knew that his best course of action was to do what she wanted. He started stroking her clit just like he used to, but instead of only using his tongue, now he used his entire body, mashing against the clit with his torso and using his arms and legs to rub the sides. He started slowly and softly and soon began to ratchet up the strength and intensity as Amber became aroused. In fact, it was easier to gauge her arousal now that he was the size of her clit, as the increased hotness and wetness made clear how she thought he was doing. Clyde ignored the outside world and just focused on his task.
It was a little strange doing it at this size, and there were a lot of differences from normal, like the tight prison of Amber's silk panties pinning Clyde against her pussy, the heat and wetness of her juices, and of course the scent of her pussy all around him. Still, years of experience guided him, and he made his goddess wife cum. Her panties (and Clyde) became soaked with her juices, and the heat felt like it was going to overpower him.
For her part, Amber had to sit down, then lie down on the ground, stretching out across her neighborhood. Her neighbors cowered in their homes as Amber moaned louder and louder, and soon all their fears came to pass, as Amber began thrashing around, knocking over some houses, smashing others to pieces, and taking out almost the entire neighborhood. It was the best orgasm of her life.
She pulled Clyde out of her panties and took a sniff of her soaking wet husband. "Wow," the giantess said. "You stink."
Amber looked up at Mary Lynn, who was still standing and watching her friend. "Thank you."