Well, Pyro had his moments, to be fair. And in this specific moment, Pyro knew he was holding the short end of the stick with no cards to play. Not only was he ill, but if it was what he feared. It would rapidly progress his conditions when using his abilities. He should probably apologize some time. Later.
There it was. The okay he needed to hear. Tony was going to hear him out at least, and then he could get back to his place, where Kitty would be waiting for him.
"I admit I don't know a ton." Pyro pushed himself up weakly leaning on the doorjamb again. "I was a victim of it, and I'm not one of them real fancy doctor types." He sighed. "I feel insanely similar to then." John slowly sauntered in past Tony and found somewhere to seat himself so he didn't fall over. Silly idea to go adventuring when ill.
"What I remember the most is that using my abilities, which were all out of whack, like now, progress the virus quicker." He weighed his words. "Which obviously made it worse, and the symptoms incredibly worse and rinse and repeat." He looked somber at Tony. "Then dead." His eyes looked to the ground as if a beaten child. "I can't let her die.." He almost pleaded. "So we have to work on this. I know.." Okay he knew it. He was probably freaking out for nothing, but it was too real, and frankly what if he wasn't wrong. John just didn't want to risk it.
"Stark, this just..." At this point John looked to Tony with pleading eyes. "I don't know what to do.."