Well, it looks like we might have T a while longer than we thought. Therefore, I feel like we need to figure out a plan for addressing how rough he plays with O. They're only 2 months apart but he has 7.5 lbs on her and is much stronger. He likes to give her "hugs" which usually involve tackling to the point of basically laying on her laughing while she cries. He has also started pulling her hair now that it's long and thick enough for him to get a good handful. Any reaction on our part seems to egg him on. He laughs hysterically. He's obviously doing it for the reaction, but ignoring it isn't an option, as it wouldn't be fair to O. He understands the word "gentle" but doesn't seem to want to be gentle with his sister. I feel bad because I end up giving him a great deal of negative attention and her more positive attention throughout the day. I know this contributes to the problem, but I can't figure out a good solution!