I would think an easy punter would be someone who you would do the deed with and both genuinely enjoy it and both genuinely be satisfied with how the meet went?
Him expecting you to perform like a seal at Sea World doesn't sound like much fun nor does it seem easy.
If I cum, I cum....if I don't, I don't but I don't fake it cause I believe they can tell if you don't with the flushed cheeks, tensed up body, sounds, fluids etc etc etc. But if you cant cum what do they expect you to do? Would they rather you faked it?
Anyway if he say's he can feel contractions on the inside when you "cum" then why not just let him munch away at your "fairy" (lol, love that) and then do some pelvic floor exercises as that's contracting your muscles anyway. Obviously try to see if it happens naturally but if it doesn't then do your exercises.
I personally would tell someone that they cant make me cum on demand and if they don't like that fact then they can go to see someone who can in future. I much prefer things to be more natural and go with the flow. I like to be comfortable and relaxed round someone for me to cum but I think we're all different.
xx