Incest
It is also an offence to have sexual relations with members of your immediate family. This includes mothers, grandmothers, aunts, sisters, nieces, daughters, granddaughters, fathers, grandfathers, uncles, brothers, nephews, sons and grandsons. Half-blood relatives are treated as equivalent to full-blood, and step-relations are also covered.
A guardian cannot have sexual relations with any foster children under the age of 21, or anyone under 18 who may be living in the house as part of the family.