I have nearly 15 years experience working inside the prisons in the State of Texas. Although I have worked as an educator, I have often been faced with the same situation. You have to assume a more confident stance and maintain a firm consistent approach to all offender questions or communication. If you show any sign that their behavior offends you, then they will use that as a tool to get under your skin. Sometimes you have to also show respect in the opposite direction but maintain your firm principles on where to draw the line. If the offender feels that you cannot be manipulated, then they won't be as likely to use you as a pawn for their games.
I currently teach Cognitive Intervention to 50 offenders. There are many books that are available in most libraries.
One good book is "Games Criminals Play".
I hope this helps you to feel more confident.