Marc, I see one small fallacy to your suggestion. You have not allowed for the possibility that the teacher has already noticed the situation, and has chosen to deal with it by not dealing with it. To bring him in to arbitrate on the mat could put the teacher in an uncomfortable position or even to have to settle the matter in a manner that was not his preferred one.
I don't think you have to go there, if you handle it the right way. You don't have to ask sensei to arbitrate. Drop that whole elaborate and unnecessary story line -- don't make it about this guy and what you think he is and what you think his motivations are. Don't say, "He thinks it's like this but I think it's like this, who's right?" -- if for no other reason than that you're quite possibly both wrong! Just say, "Sensei, I don't think I understand what we're supposed to be doing, can you help?" And then, go with what sensei tells you, and don't expect your partner to be humbled or chastened or feel put in his place or anything, because your practice shouldn't be about him
. You are there for your
practice, not to improve his
character. Get on with your practice and never mind the rest.