hi dark angel and welcome to pc!!! i'm glad you found us. it's a warm caring community.
as for your situation this is just my opinion, if a man can tell such a lie, he will lie again. he has not been truthful to you from the start. why do you feel you can trust him now? he has also lied to his first wife by engaging in a relationship with you.
you are not living as man and wife. that's because he already has a wife....and children. his first committment is to them. what type of life do u feel he can offer you other than the lonely life you have now? what if you all have children together? do u want your child to be brought up with a "sometime visit" father?
i think you have a lot of decisions to make for your future life. you deserve more than a part-time husband. marriage is a committment of both persons, not just one. i wish you well and hope things will work out for you.