When Thrawn first came to the Empire, he didn't expect to find affection with anyone. He especially never expected to find it outside his own species. Thrawn may look human, but then you get into the little details that reminds one that Thrawn's still an alien. Thrawn can't help but marvel that he and Eli's species look so similar, yet are undeniably different.

That Eli likes him too, and isn't put off by him being an alien, it makes Thrawn feel warm inside.

"You enjoyed having me in your mouth," It's not a question. Slowly, the fingers thrust in and out of Eli's lips, much as he'd done with his cock earlier. "You liked having me claim you that way."