When I refer to those first few months of the girls' lives as being rough, Mason is also a factor in this. He was used to being the center of attention, and while we still wanted to give him all he needed, that was pretty impossible. Those first couple months there was WAY more TV viewing than I ever thought I would allow. We were in "survival mode" and just tried to make it though the day (and night)!
In the beginning, Mason would have moments of pinching the baby's face and doing other not so nice things. It was (and still is) important for us to remember he isn't trying to be mean. He is simply a toddler with complicated feelings, not yet sure how to express them. He still has moments of ramming tractors into their heads or pushing them out of the way to build more train tracks, but he is learning kinder ways to express what he wants.
How did your older children handle gaining new sibling(s)?