How do you explain this to a 3 year old?

You can tell him that Mommy and Daddy arent going to live in the same house anymore.

He will live with mommy in the same house and he'll get to go visit Daddy at his house.

Reassure him that mommy and daddy love him to pieces they just not going to live together.

He'll still be able to see Daddy and spend time with him and do fun stuff just the two of them.

If he's 3 keep it simple and age appropriate explanations. I think something like I said above will do.

As he gets older he might start asking more questions and then you can answer them appropriately.

Good Luck!!

You tell him the truth! Children are much smarter than they are credited for. Surely he has seen arguements, or some indication that Mommy & Daddy aren't getting along. Just tell him that Mommy & Daddy couldn't get along well enough to live together anymore so now you don't live together. Assure him that NOTHING about him was to cause or blame for the split (children take this stuff VERY personally) assure him that the two of you love him just as much as you did when you were together. Funny, I was in the same situation, my son was 3 also and his father was his WORLD. I found my situation different than most becasue we parents were able to look past our differences and put the child first. We suffered holiday's together, spent vacation time together, all for the mental/emotional health & well being of our child. (this WHILE his new girlfriend/wife was just DOGGING me to my child!) It was a toughie, but we managed. Our son is now a top Marine, and he knows he's loved & adored by BOTH his parents. Be honest & put the child & his feelings first. You can't go wrong there.

Explain him you divorced ad what consequences it has. It's not like you are explaining this to a wall, the child will hear your words and, surprise, he will understand them, if you talk to him at all.