In the state of New York, and 47 other states, incest between adults is a criminal act. Specifically in New York a mother having sexual intercourse with her adult son is incest in the third degree, a class E felony with a sentence of either five years probation or 1-4 years in prison. Incest between adults is only legal in two states: New Jersey and Rhode Island, in New Jersey incest is not a criminal act if both participants are at least 18 years of age, in Rhode Island the age threshold is 16.
Joseph Cross (Martin Parish) also appeared in S5.E16 "Home" (2004), as Adam Nesbit.