"Karkaroff intends to flee if the Mark burns."
"Does he?" said Dumbledore softly, as Fleur Delacour and Roger Davies came giggling in from the grounds. "And are you tempted to join him?"
"No," said Snape, his black eyes on Fleur's and Roger's retreating figures. "I am not such a coward."
Complain about 'Albus Severus Potter' all you want but as far as I am concerned, it was in this moment that Harry cemented naming a child after him.
He didn't even blink. Didn't even flinch. Second guess. Or hesitate. Completely resolute and unyielding. Many other characters would have ran. But not him. Ladies and gentlemen; Severus Snape.