How can i get my 5 year old to be nicer to his little sister?

He never wants to play with her and i mean NEVER! They are one year apart from each other. I always dreamed to have two kids roughly the same age, so they could play and grow up together, be best buddies etc. Oh how wrong i was....Anything that has to do with her, it makes him mad. If she sits next to him, it's "mom shes sitting too close to me" and commence kicking each other fighting over couch space. If she wakes up after him and hes already in the living room its "oh great shes awake...i wanted to be alone.."My daughter isn't really a saint either. She learned early on how to push his buttons and at this point mastered it. She will hit him if she's mad at him for something or another. She lies and tries to get him in trouble often. Which is why i understand sometimes why he prefers to not be around her. All day long i feel like a referee trying to prevent two pint size terrors from killing each other.I try to buy games for them to play together but it always ends in tears and one child either storming off or fighting the other. They can't do board games. My son's favorite hobby is pestering me to play with him all day (well, now thats hes not in school). Ill tell him im making dinner, or tidying up and to play with his sister to which hell scream "I DONT WANT TO PLAY WITH HER, I NEVER WANT TO PLAY WITH HER" Even though my daughter is more than willing to try and i can tell it hurts her feelings. But i dont know what to do about it other than to play with both at separate times which can be pretty exhausting and time consuming.If i have my hands full and my daughter is crying over something trivial, like not being able to open a toy, ill ask my son to please help her to which he'll reply something along the lines of "No, i dont want to help her, i dont care that shes crying" to which ill get upset and go "please just open that for her, thats why shes crying" and hell go "ugh...shes so annoying...i dont want to help her" and hell just walk to another room leaving her there until i can get to her. Just no sympathy or love for her at all..it really makes me sad..Only time i see them getting along is in the park, and thats because they dont play together. My daughter will find girls to play with and my son finds boys to play with. Can someone tell me if this is a phase and my kids are normal? Or is all this crying, screaming, fighting, hating each others guts something i should work on stopping? If so, can anyone give me advice? I want to see them on the floor laughing and playing together like i used to with my siblings but i don't know if its possible with these two...Edit: I should also add, both of these kids play with opposite genders often. My daughter plays with her cousins, which are both girls and boys. My son as well. He even had a girl in his class who he considered one of his best friends and hed play with her all the time..So they are ok when dealing with other children, just not with each other. via /r/Parenting http://ift.tt/2vNRPMe