"If you had died, that would have been on Me!"
The words he had spoken to Peter seemed like a life time ago, but still held such truth.
They had failed, the Avengers had failed and he had to watch and not be able to do anything as Peter clung to him and begged!
Words had escaped Tony as Peter had clung to him. He could only hold the boy, a boy he had grown so fond of with his extrubalance and geeky pop culture references, until his would had caused Tony to lower Peter heavily to the ground.
He watched the panic in Peter's eyes as he whispered, 'I'm sorry', before he crumbled to dust in his arms. And he could do nothing!
He once heard the greatest agony wasn't being the one to die, it was being the one who survived.
He couldn't bring himself to blame Quill for taking his anger and grief out on Thanos. Hadn't he once did the same? When he had found out that the Winter Soldier had killed his Mother? He didn't try to listen to Steve, didn't want to. Not after finding out he had known and he hadn't said a word to Tony. That he had no intentions of ever telling Tony the truth.
This was why he had tried so hard to push Peter away, to keep him at arms-length, to not let his boy into his heart. Looking back, it had been a huge mistake to take a 15 year old kid into battle, and that was what the airport had turned into, a battlefield. He vowed to never bring Peter in that position again, so he had ignored the kid when they returned.
But the boy had been persistent and Tony had found himself listening to each and every voicemail and asking Karen how the boy was. And he knew after the whole Vulture incident, he had to step up to be the mentor that Peter deserved. When the spaceship had appeared, Tony had did the opposite of Germany, he had sent the kid home. But once again the kid had persisted.
Tony had been so pissed off, especially when Peter had said it was practically his fault because he designed the suit to well. But Tony had been glad to have him.
And now he was gone and there was nothing Tony could do to change that!
All Tony could do was sit and clutch his gauntlet to his chest, clutching the last pieces of Peter to his heart and mourn.