Oil and water

I have two children who seem to mix and play together as well as oil and water.  It seems weird in some ways, because they are the most like their Dad and I.  My five year old son is more like his Dad than any of the other kids. My three year old daughter is "Banks" through and through.  Their Dad and I seem to get along fairly well. :) Yet, somehow, these two must have the personalities and traits from each of us that are completely opposite.  My husband and I have always said that if we had met when we were younger, it probably never would have worked out between us.  So, maybe in the future, as they grow up, they'll end up getting along fabulously.  I just have 20 years or so to wait for that to happen and keep them from killing each other.