Michigan law 1 (old and obscure): Adultery is a felony.
Michigan law 2 (new): sexual penetration of/by another during the course of any other felony is Criminal Sexual Conduct level 1, subject to life imprisonment.
Result: Adultery specifically involving sexual penetration is CSC1, and will land you in jail for life.
For all the people who complain about "activist judges" who "eschew the laws passed by duly elected officials" and "create their own laws," I present what happens when the Court finds a point where the laws become absurd, and do nothing. As the article points out, other courts would throw this out, but Michigan's Supreme Court didn't, stating that the responsibility to fix the law lay in the Legislature, not the Courts.
If we wanted judges to simply apply the laws to the situation at hand, we could create robots plugged into a legal mainframe. But we'd get all the stupid, arcane laws coming up alongside the new, reasonable laws, and people would go to jail for idiotic reasons. Give me an activist judge any day.