As a standalone phrase, oh that's hot has circulated online as a reusable reaction clip rather than a line tied to one widely agreed scene, which is why it travels so easily between edits. Creators lift the audio and drop it over unrelated footage, letting the flirty, exaggerated tone do the joke. It became a staple of short form meme pages and soundboards because it is instantly understood, works without context, and can be aimed at people, food, cars, outfits or transformations for comic effect every time.