is incest legal

If you are defining Incest as sexual intercourse; unless the parties are legally married to each other, the answer is yes; Incest is illegal. MCL 750.520d provides: Sec. 520d. (1) A person is guilty of criminal sexual conduct in the third degree if the person engages in sexual penetration with another person and if any of the following circumstances exist: (d) That other person is related to the actor by blood or affinity to the third degree and the sexual penetration occurs under circumstances not otherwise prohibited by this chapter. It is an affirmative defense to a prosecution under this subdivision that the other person was in a position of authority over the defendant and used this authority to coerce the defendant to violate this subdivision. The defendant has the burden of proving this defense by a preponderance of the evidence. This subdivision does not apply if both persons are lawfully married to each other at the time of the alleged violation.