Might I just point out that this is one of the only times in the movie when Peter is visibly angry. He cares so, so much about May. The slightest idea of anyone, even Ned, his best friend and the person he probably trusts the most, giving May more grief, and he immediately drew the line. And he still was able to be respectful about it afterward. He thanked Ned for holding his secret. He thanked him. He realized the burden. WHAT A KID. SERIOUSLY.