You have to start as you mean to continue and finish. Here's a few thoughts
No wedding during the season;
no hanging up clothes, opening the blinds, discussions of the neighbours nocturnal habits, vacuuming the carpet, childminding duties, shopping etc during a Dees live telecast, (even with foxtel IQ and the pause and record functions I recommend you hold the line here);
any children as a result of your union to be raised as Demon Supporters - this should also include any step children if they are young enough to be swayed, recommend the employment of mother's to knit cute melbourne jumpers for toddlers
if not already a Dees supporter it is desirable she convert;
if an interstate supporter (like me) attendance at the game in your home state is mandatory, and if close enough to Canberra that too is mandatory, I recommend you make the necessary entries in her diary and make reminders as the month approaches to ensure no invites to parties, lunches, Aunty's BBQ or tickets (free or otherwise) to Pirates of Penzance etc productions are accepted on those dates;
The wearing of other team's colours to be tolerated, but not by your children
Hmmmm I'm sure there is more - but its a start for you.