As much as Roxas wants to apologize for putting Crow in this position, he pushes that urge down. This was something he wanted, and he wouldn't do Crow the disservice of wembling about it. Besides, it didn't seem like Crow was going to be backing down, so why should Roxas?

"Protection?" He asked blankly, not because he didn't know what it was, but because he didn't see why they would need that. "I don't think you can get me pregnant." That's what protection was for, according to the books. Roxas was male, Crow was male. What was the worry?