How about
:
Turn up late, wearing only a thong, a pair of white silk elbow length gloves and flourescent flip flops. (Also a set of epaulettes if flying at Oxford)
Call him 'a dirty lothario' and allege that his mother was a hamster.
Guff loudly in the cockpit after eating a curry the previous evening (N/A in open cockpit aeoplanes)
Speak to ATC in Flemish.
Take the written exams, but write with a Rowney 'Black Prince' pencil.
Have a nervous tick.
Use different phonetic alphabet (A=Amoeba, B=Binky, C=Chopsticks, D=Dibble etc etc)
After the lesson, run away cackling loudly after paying him with jelly beans.
and so on.........
I need to see a doctor