Ivan sort of watched Dmitri as he spoke, watched the variety of emotions he went through--- he was very visually expressive, unlike himself-- and wondered how much he was telling Katerina, and how much he was repeating just to convince himself he believed that. What caught him particularly was how he said nothing about how he wanted it because it would be to her. Which was, in part, quite fine-- more tender words would be saved by any for when there was some privacy, and there was nothing wrong with seeing the practical aspects of marriage (marriages solely based on spontaneous emotion rarely, if ever, ended well), but it still gave Ivan that brief moment of disquiet.
"Don't you agree, Ivan?" Dmitri asked him then. He definitely would appreciate his younger brother's insight while he was here with them, especially after Katerina had confirmed him for being a very astute person.
"It's shameful at any age, since you ask my opinion," Ivan replied frankly, having just had another sip of his tea.
"Yes, I should think so as well, but young people are expected to act shameful like that, it's acceptable," Dmitri commented. "If a young man tells you he has only been with one woman his entire life, you're inclined to think: is that so, what's wrong with him then? But it's the same way, if a man of forty tells you he's still with a new one every week."
"Perhaps," Ivan agreed, "But if you're suggesting that one should sacrifice love for experience in their youth, I might have to debate you there."
"Did I hit a sore spot, Ivan?" Dmitri joked with him, noticing the other didn't seem overly serious, the mood still somewhat light all around. He figured that this was also as good as any way to get to know his brother, to know a personal thing or two.
"Not at all..." Ivan replied, "I've had more of the latter than the former, myself." He saw no reason to not be truthful there; it wasn't said crudely.
When Dmitri laughed this time, it was the audible kind. "You're a Karamazov too!" he observed. And there was no embarrassment in this, because Katerina herself already must of knew of this trait in particular; Dmitri had thought it to be the reason, after all, their first meeting had gone the way it did.
Although Ivan's prior smile didn't dissipate entirely, it didn't seem encouraged by these words, and rather, it was at that moment he glanced at Katerina. Well, that was true. Dmitri was his half-brother, but they shared the same blood of their father... and if he thought Dmitri wasn't good enough for her, was it wrong for him to privately think that he could come to be? "It's not an intentional thing," Ivan continued, choosing to muse on the subject a little further, rather than on Katerina (although the two were nearly intertwined, at that time), "only that love is much more elusive than experience."