Long story. DS is 8 yo and DD is 5 yo. They have a stepsister that they don't know about because she pretty much hates my husband and I and has chosen to not be a part of our lives. Our DS saw a photo of her at her grandma's house and grandmother replied it's my granddaughter. Luckily DS didn't make the connection.

How do I tell him he has a half sibling who resents and hates him?

Here is the story. DH left a loveless marriage that was over for two years when we met. SD was 9 and loved the extra attention. She was an only daughter and only granddaughter so everything was always about her. Everything was fine and she absolutely liked me and I liked her, we took trips together and all was well. We got married and she was the flower girl and all was well until we started setting limits. Her mom had always hated me. We tried to set limits for spending money and she had to do minor chores and be considerate to others. we had her 40% of the time. Her mom gave her everything and she had no limits and could do whatever she wanted. When I got pregnant she was horrified, she was 12 and she was losing the "only" child and grandchild label. From the start she wanted nothing to do with our son. She commented to her friend "I hate the way she looks at him with so much love" when she saw me with my son. Her resentment grew even though we made her part of the family. She would get mad at us for not spending $200 on a swimsuit and was acting like a brat. Every time she left for her mom's house she would leave our house a mess. My son grew and when he was about 2 she would whisper mean things to him as he walked by her room to make him cry. She tried to burn him with a cookie sheet by letting him grab it as a toddler. At 14 she decided not to come over anymore. She was never the least bit interested in our DD. At 18 she told her dad she wants his money for college but wants no relationship or contact with him. DH would call her and tried to have a relationship with her without us to salvage something.

When I noticed her resenting and hating our two kids, I started having DH attend family things without us so that it could be about her when she was around him and the grandparents so our children would not steal her spotlight. But even that didn't work. Grandma thinks she is lovely and never sees her hateful side. I am at a loss, I don't want a family feud with my mother in law but I also don't want her to force some kind of relationship with our children and SD.

I don't want my mother in law to be the one to tell my children about her. My son doesn't even remember who she is. She has no contact whatsoever with us. She still occasionally sees my mother in law.

I don't want my kids around her to be honest with you. She has some narcissistic tendencies like her mother who is also bipolar. I have seen her be cold to my kids and the hate in her eyes. I saw her next to my son when he got hurt once and she walked away with a smile.

How do I tell an 8yo this? Please help me as hiding it until they are older may not be an option.

Thank you!