so i asked my 12 year old were he has been putting the dog poop and he tells me of in the big bin with the leaves and grass in it.

That's just precious! Got to love the kid for trying.

I think you have a real win-win potentially. You could tell your son that he is doing a great job cleaning up after the dog and disposing of the poo in the compost bin. That will make excellent compost for the flower beds. And he can continue to put the dog poo in that compost pile. Appreciate the work, son!
But then make another compost bin (with him) and label that compost bin for the garden and people food. Explain why you should not put dog poo into the compost bin that you will use for the food garden. At 12 years old, I think he will understand. And you can thank him again because now you will have 2 compost bins for your flower beds and your food garden. You always wanted 2 compost bins, anyway! Right?

I don't know really how much of a concern dog poo would have in a compost pile, but I have always been told that cat and dog poo compost should not be used on a food garden. I would not take a chance on using dog or cat poo in my garden compost. Better to start another compost bin now and take the win with your son.
BTW, if you also have chickens, you can tell your son that the spent coop litter can be added to the food garden compost bin, that the chicken poo will make excellent compost, but that it needs to sit for 6 months or so before it can be used. That would be a great way to teach him the differences between your chickens, cats and dogs. If you have rabbits, then that dried rabbit poo pellet can immediately be used in any of your gardens. Never too young to learn about all the wonderful things we can get from our animals.