I think Haruki getting naked was just the author trying to force a naked situation with her because she wasn't gonna get any at this point, it really was weird, if it was like "I have nothing to hide" well you didn't need to worry, I don't think Aya thought you had a third boob or you were half robot and beside, that symbolism stops making sense the moment you ask Aya to do it too, I mean, you were the one confessing.