Steve didn't have papers to weigh, not there. He wouldn't have usually thought to keep anything for himself, but it felt right, like maybe this was why it had appeared at all. The shield was a part of him, had come through time and everything by his side and he felt connected to it. So he wanted the thing that would be a physical representation of their connection to match it. As he'd held it and considered it he finally felt more confident like now he had the right thing. Because how did you buy a ring for a man like Tony Stark and have it measure up? But this, this was different.
He could understand that jealousy, Steve had experienced some in his own time. Illogical of course, but persistent. If he'd had to watch little Tony and Steve together, it would have been painful if he hadn't been able to have the Tony he'd wanted for so long.
Of course Tony would think of a sneaky way to find out his finger size, there was no doubt he was the man for the job. It took a load off Steve's shoulders and he let out a sigh. Tony was so sure, utterly sure the other him would say yes and that was a pretty nice vote of confidence and honestly Steve could use it. "I want to marry him, I just hope he wants that too," Steve said quietly.