Jack’s hair slicks itself back
Leonardo DiCaprio had amazing hair during his Titanic era, no doubt about it. It was so excellent, in fact, that it did anything it pleased. It was mysteriously untucked in one scene after being tucked behind his ear in another.
In a different scene, Jack has his hair styled naturally, but the next, it’s precisely styled back, as though he applied hair gel. Did he just rapidly slick back his hair with his spit?