Re: Problem with another aikidoka.
Punch him in the face and mention "a hole in his knowledge". You just are trying to help after all.
One of the George Ledyard type punches that makes it clear to all that one has been punched in the face without actually having to punch them in the face kind of punches. Regular punches work too but tend to get blood everywhere. If they don't appreciate either kind of punch then they really are not there to improve their knowledge and so have little to add to yours.
Of course, if they won't train with you then you will have to resort to jumping out of bushes and scare the crap out of them and shout 'another hole' . When you come to the realization that you have become a stalker you might want to tone it down a bit. Then you can just call him 'hole' in a fraternal kind of way as a little aiki nickname. Just trying to help after all.