Hello,
I am a mother of 3 and my husband is spanish and i am from the United States. He speaks spanish and english and i speak english and i understand spanish but i do not want to speak spanish. We speak only english to our kids and we teach them a few words at a time in spanish often. When i was trying to teach my daughter spanish when she was 5 and my middle son was 3. My son would try to learn at the same time.
BUT he was counting his numbers like this.
One, two, three, cuatro, cinco, six, seven, ocho, nueve, ten.
When i heard him counting like this, I knew that teaching them spanish at that time was not good for them.
I feel like we live here in the United States and we need to learn how to talk in English FIRST and then after they understand English well and they can understand the difference between them both then i will make sure that they learn how to speak in Spanish as well.
My daughter and middle son are both in school now and school is not easy. They will need to know how to talk very well in ENGLISH.
If your child gets confused between 3 different languages then things might get harder on the child and then the child might not enjoy learning.
This is really all up to you and your husband on what you want to do, not all familys are the same.
Remember your son is only little once and trust me when i tell you this "they really do grow up to fast" so enjoy him while he is little and he has his whole life to learn and grow. NO RUSH.
I wish you the best.