Accuse Amy of lying
From Create Your Own Story
"She's lying!" You exclaim.
"Would I lie, Mrs. Smith?" She says back.
"I can't blindly take your word over is. However, if you give me the tests, I may be able to find the truth. If the answers were copied, then Amy is telling the truth." She glances on both papers. "Very interesting. These answers are the same. Mr. Robertson, see me after class."
The class ends. "I don't know what to do with you, Mr. Robertson. You are currently failing this class, and I have proof of you lying to me. What do you make of this?"