My son was 2 in Jan, and I have a 9 month old baby girl.
Ds was always very loving toward dd, never had any issues when she was born.
But now, since she is crawling, he is being awful. He still have loving moments where he kisses her, or if she is upset will tell me she is sad. But it is getting to the point im scared to put her down on the floor. He will randomly, with no sign that he is about to do so, push her over, grab her hair, body slam her! He then runs off laughing!
I go and pick up dd and comfort her, as she is screaming at this point, then sit next to ds and say something along the lines of, we dont do that, that hurt dd, she is sad now and has a hurt. He will then go "awww" and giver her a kiss. I think he understands that, as when he is hurt, he always comes over to me, points to his hurt and asks for a kiss better!..However he is also starting to do things like bite his own finger, or scrape his teeth over his finger, so he comes over to say he has a hurt.
I have been very careful to not let him feel left out, if anything I went the other way, and excluded dd, and I suffered and still do suffer from pnd after dd, and had huge detachment issues with her, and dh dealt with her for the first 6 months! The only thing I did with her was feed her.
But it seems like his aggressive behaviour toward dd is getting worse. I was sat next to dd earlier and he came over and tried to push her over, and even though I was asking him to stop, and moving dd out of his way, he was just desperately following trying to push her!