"Levicorpus!" Severus declared suddenly. His face looked like stone and it was obvious he was not happy. A third year Slytherin was suddenly hanging by his ankle and everyone looked in awe. No one knew about this spell. It was his own. Lily Evans had the beginnings of tears in her eyes. She hadn't been called a mud blood before. Never to her face at least.
"Let me down you little brat!" As the Slytherin declared this everyone from his house glared straight at Severus Snape. "Alright Sev!" yelled, out of nowhere, James Potter. Sirius Black followed with a cheer of approval. "Never." Severus began. "Call Lily Evans a mud blood again, you pureblood git!" He let down the Slytherin with a huff.
" Good one Sev, did you find that in some old book? You gotta teach me!" The Slytherins were furiously stomping off, the victim of Snape's Levicorpus especially outraged. "Sev…you didn't have to do that, it's something I've got to deal with…" Severus turned to face her. "Never. Never while I'm around…no one will ever call you a mud blood. You're too good of a witch, and too good of a person to have that word thrown at you. All the wizard blood in the world couldn't make them a better wizard or witch than you!"
All around Snape people were giving him looks of approval. James Potter was grinning and Sirius Black, who was arguably his worst critic, gave him a cheer. Remus Lupin even nodded approvingly. How had he come from a boy who was desperate to please his mother to a boy desperate to protect Lily Evans? He knew the answer. He looked around him and knew that it was his love for Lily that made him look at him like that.
They looked at him with approval because he was truly a Gryffindor.