Section 720 ILCS 5/11-11 - Sexual Relations Within Families(a) A person commits sexual relations within families if he or she: (1) Commits an act of sexual penetration as defined in Section 11-0.1 of this Code; and(2) The person knows that he or she is related to the other person as follows: (i) Brother or sister, either of the whole blood or the half blood; or (ii) Father or mother, when the child, regardless of legitimacy and regardless of whether the child was of the whole blood or half-blood or was adopted, was 18 years of age or over when the act was committed; or (iii) Stepfather or stepmother, when the stepchild was 18 years of age or over when the act was committed; or (iv) Aunt or uncle, when the niece or nephew was 18 years of age or over when the act was committed; or (v) Great-aunt or great-uncle, when the grand-niece or grand-nephew was 18 years of age or over when the act was committed; or (vi) Grandparent or step-grandparent, when the grandchild or step-grandchild was 18 years of age or over when the act was committed.(b) Sentence. Sexual relations within families is a Class 3 felony.Amended by P.A. 096-1551,§ 2-5, eff. 7/1/2011.Amended by P.A. 096-0233,§ 5, eff. 1/1/2010.