Homegoing, by Frederik Pohl
Sandy Washington was a pretty normal guy. The only unusual thing about him was that Sandy had been raised by aliens on their spaceship. The Hakh'hli had done everything they could to give Sandy an Earth-type boyhood. Now, finally, the Hakh'hli were bringing Sandy home to Earth. And while they were at it, they intended to give humanity some extraordinary gifts. The Hakh'hli seemed to have Sandy's & humanity's best interests at heart. But the people of Earth weren't so sure.
By the time Obie came back, looking chipper and pleased with himself, they had reached the boiling point. “Oberon, you’re a hoo-hik turd!” Polly thundered, and Helen and Tanya chimed in.
There's a character named Bottom:
“Were there lots of eggs?” Bottom asked enviously.
And pithing the cubs:
“You did it already,” Sandy pointed out. “I’m sorry, Obie. I guess I just don’t like pithing cubs.”
“What’s the matter, Sandy? You’ve done it before.”
“I didn’t like it then, either,” Lysander confessed.
“But we have to pith them,” Obie said reasonably. “For their own sake, you know? It keeps them from being too smart.”
And here's the poem:
I dream of you each day
and think of you asleep
and wish the experience
of treading upon your
soil would come, O
it has the