not your parents' son, but the son of a person that one of your parents has married
Their father would assume the role of stepbrother in relation to themselves.
After the remarriage, she gained a stepbrother who quickly became a close companion.
Family dynamics can change significantly with the addition of stepbrothers and stepsisters.
The relationship between a stepbrother and stepsister may evolve over time.
Holidays often involve gatherings with both biological and stepbrothers.
