
Then he doesn't want to talk about it. It's simple really. Plus the truth isn't always pleasant to hear unfortunately because if it was then people wouldn't lie. He clearly went through something and isn't ready to talk about it. And how is having an undertone to something mean you're rude. He was just firm in his decision not to talk about. Sure it really hurt her feelings, it would have hurt anybodies feelings. And it hurt because she had the truth thrown in her face which is harsh but he had to make it clear that this is who he is now. Like he said the past is the past. It's sad because you really can't change it.
You want him to sugarcoat his words and mask his frustration and let him talk about something that clearly makes him comfortable. I'll stick by what I've said, he wasn't rude. He was blunt and straightforward.

Maybe he felt comfortable enough to honestly just speak his thoughts on the matter. I've read from chapter 1 til 11 and I expected him to be rude and harsh as the comments said but tbh I didn't feel it. She expected something and he didn't live up to the expectations she had placed on him. Hence the disappointment
It wasn't rude. Just not sugarcoated. What he said was the truth. Nothing more, nothing less