AceShowbiz -

Daniel Baldwin and Robin Sue Hertz Hempel are set to wed. His representative tells PEOPLE that the "Homicide: Life on the Street" alum proposed to his love on Saturday, November 22 at the Fort Lauderdale Film Festival, where he was promoting his new movie "The Wisdom to Know the Difference".

In a photo obtained by the site, Robin can be seen showing off her engagement ring. Daniel says he "slipped the ring into a glass of cranberry juice" to surprise Robin. The "Grey Gardens" actor adds, "Upon finding the ring amongst the ice, Robin exclaimed, 'Yes!' " Daniel designed the ring, which features nearly five carats with a marquise-cut diamond accented by baguette diamonds, by himself.

Alec Baldwin's brother tells the site, "I couldn't be more overjoyed Robin said yes. Next to the birth of my children, this is the happiest day of my life."

Daniel is already a father to four daughters, 30-year-old Kahlea, 20-year-old Alexandra, 6-year-old Avis, 5-year-old Finley, and a son, 18-year old Atticus, from previous relationships.