They are especially asking for proof starting in April 2012 when we still lived in the basement suite.
Starting May 2013, everything is easier because it's our own place with lots of documents. And that's the time when our life insurance started, the condo insurance, the car insurance... Everything in both names.
Just before that we only have the letter from the landlord confirming that I lived there with rental agreement in my boyfriend's name + mail I received + same address on driver's licence + joint health insurance + 3 holidays we went together + tons of pictures + 4 statutory declarations from friends and family...