From my experience I would say Communication is the most important component to a happy kilting within a marriage. You might want to sit down with your wife and explain to her why it is you want to don the kilt, let her see this forum, and as far as the "fashion trend" comment, you might want to direct your browser to
http://www.dressedtokilt.com/
or
http://www.21stcenturykilts.com/home.htm

Hope this helps