While Harry was unaware that Ron had paid for both his and Harry's meal at the current moment, he'd be peeved later when that money showed back up. It wasn't that he didn't think Ron could buy both, it was simply the fact that he could buy his own food. It was only right. As it were, he was quite glad to see his own sandwich. He was bloody starving. Why? He had no idea. He just was.
Harry watched their short conversation. Yeah, something was definitely up, but if they didn't want to tell him that was their prerogative. He'd survive. "Yeah, I don't see a problem with that." he shrugged, catching Hermione's tone but not commenting. "As long as there's no Slytherin bashing. I personally don't want to end up hexed six ways to Sunday."
He might have to do a little bit of convincing on his part, but a small get together really couldn't hurt anyone...right?