thewayneiac: Rei has had little contact with others and is thus so socially inept that she has no idea of how her nudity might affect a teenage boy. The counterpart to this scene is in Ep. 24, where Kaworu doesn't realize how Shinji will interpret his suggestion that they sleep together.
K9Thefirst1: Well, while it's there: Could someone well versed in Japanese culture explain to the rest of us the reasons sociological and/or psychological behind the Japanese and their obsession with girl's panties? Seriously: I don't even-
thewayneiac: What's to explain? You don't normally see them because they are under the outer garments and they've been in contact with the girl's privates. It's also not solely a japanese thing. If you're versed at all in U.S. college hijinx, you've probably heard of "panty raids". I'm surprised Shinji didn't grab a souvenir before following her to HQ.
