Having step kids in a marriage is always a double edged sword.
They will be difficult at the start but if you continuosly show them love and understand that most times they are abit jealous that their mum has someone in her life taking all the attention. That is when they are still kids.
But as they get older and leave the house they are actually happy for the companionship their mother has.
I know someone the step kids was horrible to start of her marriage. She perceivered cos of the love of her husband. The husband also cautioned them best he could.
They are all married now along with her two kids based abroad. Yearly she goes to visits these kids abroad. Even when they give birth she's the one that goes to help them.
I don't know their case anyway but it seems he didn't get along with the ki