I'm the boyfriend of a now 4 year old's mother and I have been in the little boy's life for about 2 years. We have a good bond, although I don't live with them and see them 2 weeks every 4.
My ex and I had a dog before we split and eventually I became the full time owner of the dog. She is the most timid and good natured dog and has never bitten or attacked anyone and I don't believe she has it in her. When I visit my girlfriend or she visits me I take the dog. The little boy loves the dog and follows it everywhere. Sometimes he gets a bit too boisterous and so we remind him to be gentle. I am forever trying to stop him from playing with toys on her or pressing his hand into her head or back.
However, he seems to think it's great fun to purposefully try and hurt her. I'm sure it is just him being inquisitive, but he also says things like "let's squish Holly (dog)". Today as I was leaving to come home (I live 200 miles away), he wanted to pass me a laptop charger and in doing so rather than give it to me, he dropped it on the dog's head (dog was sitting on my lap). I could see from his expression before and after that he meant to do it. The dog yelped and when we tried to say he shouldn't have done it he simply ran off. When he got back he apologized, but laughing as he did so and then wanted to play. Which made me think his apology was simply to be able to play. The fact is I am fed up with him being reminded 20-30 times a day to stop dropping things and playing with his toys on the dog. He just does it anyway.
I don't have children myself so this is my first experience of trying to help raise a child. My bond with the child is very good and we get on really well with him even wanting me to stay. The dad is still around, but he is a Narcissist and goes through life blaming everyone else for his actions/faults. I don't want him growing up to be like his dad.
I keep falling out with his mum as she thinks I am too hard (which I possibly am) and I think she doesn't make him aware of his actions and the consequences firmly enough. For example when he came back to apologize she asked him if it was an accident, which he naturally said yes. To me this is not being responsible for your actions and justifying them!