Junks12 said:
We have never lived together, we are not married or common law. But we have been together for over 3 years and have a 17 month old son.
In practice, your only possibility will probably be to either get married or else arrange to live together for a year in some place you're both allowed to be. (I have a feeling it might be difficult for your boyfriend to get a visitor visa for Canada in these circumstances. I imagine St. Lucia would be more liberal the other way for you.)
If you haven't lived together and aren't married, the only possibility is the so-called "conjugal partner" category. However, the government is extremely stringent and tends to allow it only when people have very serious circumstances keeping them apart. (For example, a same-sex couple in a country where they would face persecution if they lived together.) For most people, this is out of the question.
For a boy who needs his father, I'm not in a position to say whether this would qualify, but the matter of why you wouldn't just get married would likely be raised by CIC. You might find yourself in a position of having to mount a legal challenge to the current administrative framework. There has been some mention of a possible "right not to marry." If you feel like trying this, speak to a good immigration lawyer.
I presume your boyfriend is most likely named on the child's birth certificate, but if this isn't the case, you might also want to speak to a lawyer in such a circumstance.