Mercedes thinks this loser deserves nothing better. He is to feel her spit in his face. She is spitting at him, with the gobs of spittle landing smack in his face. She is then spitting at her boots, knowing that this loser will come crawling, eager to lick the spit off her boots. Yes, that's how it should be! And don't forget to open your mouth wide so that Mercedes can take her aim at it.