Remus was wise, probably, to be worried and a little scared -- he'd been traversing their own world for a long time now while being a werewolf and even though it was a known thing there, people were against it to the point of -- well. Werewolves were not looked upon kindly. They knew that. So it was frightening to introduce the idea to people who may or may not have ever seen or heard of it in their own lands.
Not a good feeling.
But Sirius had never been one for dwelling on negative emotions if he could help it, and so he shifted again, pulling himself away from Remus' lap in order to sit up properly and look his friend in the eye. "Hey," he said, and his expression was easy, practically carefree. Confident. "It'll be okay. Promise." Sirius didn't know if he actually could promise things like that, but he was going to do it. Remus might have worried for making problems for him, but Sirius never saw it like that, not once. And it definitely wasn't on his list of concerns. If there was trouble, there was trouble, but it'd be for the two of them to handle. Like they did.