If Pietro didn't want anything, he would have gladly walked away. If he really wanted to help Tony (as if he needed help, as if there was anything Pietro could do to raise the dead or fit this stubborn team back together or put the Tower back in place, as if Tony couldn't deal with it on his own and had to be treated like a child), he would have gladly walked away. This wasn't about Tony at all. And why should it be? Pietro, desperate, still grabbed for him, in the hall now where anyone could watch him and make Tony the villain when he pushed Pietro away. He wanted to do so much more, make him swallow a tooth for braying about all the help Tony needed, but Tony went stiff, fists raised only to bar his arms between them and keep Pietro from getting too close. Why did he fight it? Pietro could have it. He had to know how much Tony hated him and hated himself for letting Pietro wrestle him into that hug, but he still took it. Tony could never get it right anyway. Whatever Pietro wanted, Tony didn't have any business denying him.