Would I be a snitch if I went to the principal for help?

Some kid took my white American Eagle shades back in April, he asked to borrow them. I said ok. Well now its the beginning of June and I really want them back. Just today, I realized that he was lying to me the whole time. I drove down the road by my school and I saw him wearing them, he's never going to give them back to me :( So when Monday comes, I plan on stopping by the Principal's office and maybe he could help me. I don't wanna be known as a snitch, but he did disrespect me by lying and attempting to steal.