Bruce's eyes fell on where Natasha's hand was on his and offered her a smile, appreciative of the fact she'd never been afraid to touch him. Some people were and others not so much, Natasha was one of those peole.
"Yeaaaaah you could say that," he drawled with a grimace. "Thor has a sister - did you know he had a sister?" Anyways he waved off that point. "Black hair, kind of crazy, determined to dominate everybody and everything. She basically tore through Asgard with this giant wolf," and on the description of giant his hands came into the expression to emphasise just how big that wolf was, "and the only way to stop her was Thor to bring about something called Ragnarok by letting this demon called Surtur go all Armageddon on Asgard."