The joke is not about “eating”, the AI just tried to guess the meaning but kinda failed. The joke is about two famous civil war figures in the USSR (Chapayev and Pet’ka), which often are subjects of crass jokes.

The first half is correct. Pet’ka asks Chapayev to explain the definition of “nuance”, as it’s a foreign word that he doesn’t understand. Chapayev asks him to put his pants down and puts his dick in Pet’ka’s ass. Pet’ka is perplexed.

Chapayev says: “See, we’re both in a “dick in ass” situation. But there’s a nuance.”

And they still try to downplay it - “the worst since Assad”