Get lost.
Speak as Tony
Speak as Stephen
Stephen: Get lost. I'm busy.
Tony: Come on. I just want to see what you are doing.
Stephen: I said that I'm busy. Please just leave me alone.
Tony: At least tell me what you are doing.
Stephen: If I tell you what I am doing, then will you get lost?
Tony: Deal.
Stephen: I'm designing a T-shirt for my band. I'm going to try to sell them at our concerts.
Tony: That's so cool. Can I help? I'm great a designer.
Stephen: No! You said you would leave me alone if I told you. I will show you after I finish.
Tony: Okay. I'll leave you alone, but you'd better show me when you're done.