There is a high chance of refusal because you had a relationship with this woman before, during and after your married to the Canadian. I'm sure you can see why this is a problem - it makes it look like your marriage to the Canadian was fake. I would recommend that you work with a very good immigration lawyer (not consultant) when you file your application.i had some relations with women but i was free. we are ready to make DNA and go interview, why it will be refusal if i am canadian, and want to take my family with me, i will make everything if they refusal, and dont give chance, , i will come back to my boys, i don't want that they grow up without father. i didn't want such responsibiities that are two boy, but if it is life fortune that god send me it's priority for me to be father