"It gets better, I promise. And I think it'll be better for you than it was for me anyway, because I didn't have a very good angle," he doesn't explain that. Either Yuri knows about what's coming or he doesn't and Otabek is fine with moving slow and letting Yuri know that he'll stop, but he's not really interested in providing anatomy lessons.

He's scissoring his fingers a little bit, testing his reaction, but only for a moment before he's reaching deeper, deliberately angling like the description he'd read told him to, searching for the right spot...

It is almost certain he is not ready for the reaction it's going to get, when he finds it.