Lorenzo
While he had only the slightest bit of energy, he did not lose all consciousness rather than the ability to move freely. He had blacked out, but just being held like this gave him enough strength to not lose himself. How he wished it hadn't been the case.
The dead may not speak, but they are not silent. And what he could barely hear with his ounce of remaining strength, he did not like. It angered him, and most of all, it hurt.
He knew she was right, of course. No matter how much he'd shut his ears off, he knew the ugly truth. But the fact she was the one to say it pissed him off more than anything in the world. Even if he had the strength to do it, he couldn't frown. Laughing it off was much easier. If she was happy, he'd be happy.
"Bwahahaha! Wife? Woah, I'm almost jealous Medaka! Y'know, it's not like I could sleep even if I wanted to. You're such a worrywart you know? Just leave me somewhere and have fun, I'll be fine."
Normally, this would sound incredibly passive aggressive in context, but this sounded different. It's almost like he was asking her to throw him away and forget about him. He didn't have the strength to move, nor did he have anywhere to go, but if his pride was wounded to such a degree, he was the sort of person who'd rather be left alone than have his own misery forced on others.
For you see, Lorenzo is what you would call an unreliable narrator.