Sibling
Cross Siblings (Cross Brothers/Cross Sisters): These types of siblings are individuals who share one or more half-siblings; if one person has at least one maternal half-sibling and at least one paternal half-sibling, the maternal and paternal half-siblings are cross-siblings to each other. Stepsiblings are not cross-siblings unless their married parents have a child together. Alternatively, cross-siblings may not be stepsiblings at all, in the event that the respective parents have a child without marrying, or the cross-siblings are born after the parents of the mutual half-sibling have separated. Cross-siblings are not biologically related, unless the parents have a biological relationship irrespective of their children's cross-sibling status.