I'm going to let my friend unknowingly drink from my water glass
Why would you want him to drink from your glass?
Because I'm planning to set him up because he called for me for help and  I am annoyed.
Your friend may not appreciate being in contact with your germs. He may even get sick as a result and end up in the hospital.
My goal is to catch my friend and have fun once I make him feel guilty.
Still you could have told him no you didn't want to help. You have the right to tell other people the truth of how you feel, if you let it bottle up you may resent him one day.