Chris Hemsworth doesn’t think much about his butt in Thor: Love and Thunder because he has seen it before. Way to brag about it!
However, most of us haven’t, which is why it’s such a BIG deal. Hemsworth’s butt marks the first legitimate nudity in the MCU, as evident when Zeus accidentally undresses him for the entire Olympian court to see. The sight of Thor’s god-like buttocks (plus the front parts hidden from meta-viewers) causes a mass faint.