The widow of a wealthy Manhattan businessman claims she’s been shut out of her chunk of his $60 million estate by her husband’s ex-girlfriend.

Louis Srybnik, who co-owned Life Science Advances Inc. and Premier Atlantic Properties with his brother, Simon, left instructions that his wife Caroline should get a $3 million payment immediately upon his death, she said in court papers.

But instead of doling out the payment as Louis directed, Darby MacFarlane — a co-executor of the will and a long-ago girlfriend of deceased — “directed payments of approximately $18 million to charitable foundation[s]” that she controlled, Caroline charges in her legal filing.

MacFarlane, 75, dated Louis about 50 years ago and re-appeared in his life in the years before his 2015 death at age 91. Simon Srybnik died in 2018 at 102.

“She inserted herself into their business and personal lives, and convinced the brothers and their wives that they needed her ‘assistance’ and ‘protection,’” Caroline claims in Manhattan Surrogate Court papers.

MacFarlane helped the brothers draft new wills and allegedly “pressured” Caroline to go to court to remove Simon Srybnik as co-executor of Louis’ estate.

In a separate court filing, MacFarlane claims Caroline improperly withdrew more than $1 million from the estate to reimburse herself for expenses and called the conduct “self-serving.”

A lawyer for MacFarlane did not respond to a message.