You just know I had to google it:

http://www.google.com/search?sourcei...316&q=Okimawiw

Got more than one site with it too, including definitions.

Of course your son need never know why your calling your dominant that, it could easily be taken as a term of endearment. In any event I think it's romantic.

Not that its nessesary to have any special reference or titular distinction between partners. I am sure you both know the score regardless of which title if any you use, in private or otherwise.