Misguided
When the Maximoff twins got their powers, Wanda read the HYDRA agents' minds and found out that they were the ones that ordered the bombs to be dropped on their house and that they did it to continue the civil war and get more vengeful volunteers. The HYDRA brainwash them to shut them up and get them to comply.
When they attack Tony in the bunker, JARVIS uses the suit to throw them into the wall, which breaks their brainwashing. Tony takes them to the Tower to protect them from any leftover HYDRA.
Once there, they tell him about their parents and he says he's sorry for them. They say they're sorry for his parents as well. They had believed that he knew that they had been killed by HYDRA because both Rogers and Romanoff knew. Tony goes into shock. Wanda had told him to stay away from the scepter because it leaks malevolence, so he had put it in a lead box, so Ultron never comes online. Due to the party happening, Pietro, Wanda, Rhodey, Bruce, Helen and Thor have a sleepover in a big nest of pillows and blankets, and (timeline what timeline) when Thor finds out that Tony is catatonic due to the shock, he remembers that Loki had a spell to help with grief that he sometimes used in their adventures to help any victims, so he brings him from Asgard to help Tony, and after that Tony invites him to stay. The spell is painful, but Loki equates it to pouring hot water on an infected wound to clean it out so that it can heal.