My teenager is about to meet his half-siblings (same father) for the first time. How do I prepare him?

Teenagers need honest information and room to express their feelings before the meeting, not just instructions to behave nicely. Unlike young children, teenagers may feel angry, jealous or awkward, and those feelings should be accepted first. Sit with him and explain the family situation calmly, then listen to what is on his mind. Give him choices about how the meeting takes place, for example in a neutral public place, so that he feels respected. Avoid forcing put-on cheerfulness, because a sincere relationship takes time. Assure him that accepting new siblings does not reduce his place in your heart. See children in polygyny for further guidance.