Maybe it's a section that highlights a particular theme or setting from the entire novel. Or it could be a snippet that showcases the author's writing style or a key event.
Steve Irwin was a wildlife expert. He was known for his enthusiastic and hands - on approach to wildlife. He wasn't afraid to get up close and personal with the animals, whether it was a huge crocodile or a venomous snake.
I don't know who Steve Crisp is in this story without more details. He could be an ordinary person with an extraordinary experience, or someone with a special talent.
On the other hand, Steve might be more understanding than expected. He knows about Bucky's past traumas and could suspect that something else is at play. So, instead of immediately resisting, he might play along for a while, waiting for the right moment to figure out what's really going on and how to help Bucky.
You can start by looking on Archive of Our Own (AO3). It has a large collection of fanfictions, including ones about Steve and Tony. Just search for the relevant tags and you'll likely find many great stories.
In the context of this fanfic, Catherine Rollins and Steve are likely characters created by the fanfic author. They could be original characters, or they might be based on existing characters from a particular show, movie, or book. Without more context, it's hard to say exactly who they are other than two individuals whose relationship is central to the story where Catherine makes Steve cry.
He could also be very angry. If he feels blindsided by the break - up, he might lash out at Catherine. He could accuse her of leading him on or not being honest about her feelings all along, and this anger could be his way of dealing with the pain of the break - up.
One possible reason could be Steve's strong sense of loyalty to Bucky. Maybe he feels that he owes Bucky so much after all they've been through. He might be so focused on helping Bucky or being there for him that he unconsciously ignores Tony.