How long have you been in this relationship? Is the relationship common knowledge to all your friends and family members? Have you lives become intertwined on all levels including financial, i.e. join bank accounts, insurance policies, wills, etc.?
We've been together three years this April. Yes to all of the above.
If I recall correctly, Allison's application was solid because of significant proof of all of the above. Have you read OP Manual 2? You might want to give that a look.
http://www.cic.gc.ca/english/resources/manuals/op/op02-eng.pdf