Headscratchers / The Avenging Spider

• It's been stated out-of-universe that before Endgame that Steve was actually always worthy of wielding Mjolnir, but he didn't do so because he didn't want to humiliate Thor in front of the other Avengers. In Age of Ultron, Thor was nervous when he saw that Steve was capable of moving Mjolnir slightly. So why was Thor not nervous or upset that Peter did lift Mjolnir at all?
  • One possibility is that Thor already saw Peter as a good friend.