If the hurt is physical, Tony could retaliate in self - defense. He has his Iron Man suits, which he could use to protect himself while still trying to avoid causing too much harm to his former friends. At the same time, he would be deeply hurt emotionally and might start to question his relationships with the Avengers.
He could also go into a state of isolation. Tony might retreat to one of his many properties, cut off communication with the outside world, and start to work on some new technology or project as a way to cope with the betrayal and pain. He might be thinking about how to prove his innocence or how to make the Avengers see the truth.
He could also become more defiant. Instead of trying to win back their favor, he might double - down on his actions and beliefs. For instance, if they hate him for his use of a particular technology, he might continue to develop it just to prove them wrong.
Tony would likely be defiant. He's not the type to cower in the face of danger. He might immediately start looking for weaknesses in Thanos' setup and try to escape on his own terms.
Peter might be initially shocked and a bit scared. After all, Tony is like a mentor to him. But then he could become defensive, trying to explain his actions or point of view.
Peter is likely to be in awe. He might be a bit nervous at first, but also extremely excited. He has looked up to the Avengers for a long time, so meeting them would be like a dream come true. He would probably be stuttering a bit as he tries to introduce himself and show his respect.
Tony would probably be extremely hurt. He trusted his team, and betrayal would cut deep. He might initially be in denial, not wanting to believe that his friends could turn on him.
Thor could be angry. He's a proud warrior and being kicked out like that might be seen as an insult. He might even challenge Tony in some way, either verbally or physically. However, he also has a sense of honor and might listen to Tony's reasons if given the chance.
Another way the story can develop is that the remaining Avengers try to win Tony back. They realize their mistakes and make efforts to reconcile with him. This could involve a lot of emotional scenes and character growth for both Tony and the other Avengers.
Well, in some fanfiction stories. Sometimes the scenario of Steve cheating on Tony is used to show the fragility of their relationship. It could be that Steve is put in a difficult situation where he feels pressured or confused. For instance, there could be a situation where Steve believes Tony has betrayed him first in some way, so he retaliates in a wrong way by being unfaithful, but this is all within the creative realm of fanfiction.
In some fanfictions, Tony might help Spiderman by providing him with advanced technology. For example, he could give Spiderman a new suit with enhanced features like better web - shooters or stronger defense mechanisms. This would help Spiderman in his battles against various villains.
They might be in shock. Tony has a complex past, and seeing it all unfold could leave them speechless.