Robert F. Kennedy Jr.'s reputation has taken a new hit this week, as revelations emerge about his clandestine relationship with a Connecticut socialite, which unfolded while he was engaged to actress Cheryl Hines. RadarOnline.com has brought to light these alarming details of Kennedy's infidelity.

With Kennedy's racy diary of womanizing exploits and so-called "lust demons" resurfacing, more discomforting details are coming to light. Among these are claims that Hines, best known for her role in "Curb Your Enthusiasm," had to confront her then-fiancé about an affair just before their wedding.

Kennedy's secret lover was a 42-year-old mother of four who was dealing with her own marital problems at the time. It's claimed that Kennedy seized the opportunity of her vulnerability, initiated by their shared gym routine.

While her identity remains confidential, the woman did not deny her involvement with Kennedy. An inside source stated, "Bobby was well aware that she was going through a bitter divorce, and he took advantage of her at a very vulnerable time."

According to the same source, "He's a no-good horndog," who seduced her with his charisma, leading her to believe that a serious relationship, even a possible marriage, could materialize.

However, unbeknownst to her, Kennedy was deeply involved with Cheryl Hines, who is now 57. The revelation has left her feeling deceived and hurt by Kennedy's misleading actions.

Kennedy's secret lover and her estranged husband, a prosperous medical professional, were part of Kennedy's social circle and frequented the same gym in Armonk, N.Y. According to the source, "When Bobby eyeballed the woman in a hot exercise outfit at the gym, he didn't waste a minute before putting on a full-court press to win her over to be more than just friends."

Even as his relationship with Hines was escalating, Kennedy invited his mistress to accompany him to a Seattle event in April 2013. Despite his engagement, he wasn't concerned about getting caught. The source added, "Now the woman has become just another notch on his belt.”

Kennedy's unfaithfulness came under scrutiny following the tragic suicide of his estranged wife, Mary Richardson, in May 2012. After this devastating incident, it was revealed that Kennedy had multiple affairs during their marriage.

RFK Jr.’s controversial sexual exploits were initially exposed in 2013 following the release of a 398-page diary, which documented not only his daily life, speeches, and family life during 2001, but also the names of 37 women he claimed to have slept with during this time.

This scandalous diary, infused with his Catholic guilt over his infidelities, mirrors the behavioral patterns of his uncles, President John F. Kennedy, and U.S. Sen. Ted Kennedy, as well as his assassinated father.