The pair had more of a "dating relationship" since they didn't share housing, finances or property or present themselves as a couple in public, Justice John E. Wallace Jr. wrote for the unanimous court.
The 7-0 ruling, in which two justices wrote separate concurring opinions, is the third time courts have rebuffed Helen M. Devaney.
Devaney was 23 when she started having an affair in 1983 with her boss, 51-year-old Francis A. L'Esperance Jr., an ophthalmologist who had been married for 20 years. She worked for him as a receptionist.
They regularly had dinner together, but L'Esperance went home each night to his wife. He did buy her a car and pay for her college degrees.
But court papers said L'Esperance never followed through on promises to divorce and have a child with Devaney, ultimately telling her in August 2003 that he no longer wanted another child.
He evicted her in 2004 from a North Bergen condominium he had bought her, according to court papers, after she would not let him enter when a new boyfriend was visiting.
Devaney sued for palimony later that year, asserting L'Esperance breached a promise to support her for life.
A trial court found that while Devaney had become financially dependent on L'Esperance, he never promised lifetime support.
The Supreme Court determined that living together is not essential to gain support, rather, "It is the promise to support, expressed or implied, coupled with a marital-type relationship, that are the indispensable elements to support a valid claim for palimony."
However, "... in most successful palimony cases, cohabitation will be present."
Devaney lawyer JoAnne Juliano Giger said she was disappointed that a 20-year relationship was found undeserving of support, but glad that cohabitation was not required. The lawyer did not know whether Devaney, who had been engaged after she sued, had married.
L'Esperance has remained married, said his lawyer, William Goldberg, who said a successful palimony claim in this case "would be creating the concept of judicial bigamy."
"It would actually upset the fabric of marriage to create a situation where the girlfriend could participate in the family assets," Goldberg said. "This is a woman who obviously knew he was married."
"She lived a great life at his expense," Goldberg said. "I think she relied on his largesse to a point that was beyond his expectation."
