Tom Wopat got handsy with a minor -- a 16-year-old actress -- on the set of his play ... according to authorities who've added new charges against him.
Police say they interviewed the girl 2 weeks after the ex 'Dukes of Hazzard' star was arrested in Waltham, Mass. for felony indecent assault -- he allegedly put his finger in a woman's butt crack. According to new docs, he also poked a minor in her stomach with his finger. The alleged victim was one of his co-stars on the production of "42nd Street."
According to the docs, he told his underage co-star, "I'm a creepy old man, you're really talented and really cute." She told cops she ignored him, but his words made her uncomfortable.
Shortly after that exchange, during rehearsal, she says he struck her butt with his script ... and said, "Nice butt." As for poking her in the stomach -- she says she was especially creeped out because she was wearing a cropped top, and he touched her bare skin.
The alleged victim says an adult on-set told Wopat, "Don't flirt with this girl, she's only 16." She claims Wopat responded, "Don't worry because my wife is 17 years younger than me so I'm good."
He's now facing a new indecent assault and battery charge for the alleged incident ... as well as 2 additional charges of accosting and annoying.