He attended the Findlay High School prom on Saturday, perhaps foreiting his graduation.
Heritage, which did not answer calls from ABCNews.com, has said that he will get an "incomplete" on his remaining assignments and won't be allowed to attend his May 24 graduation.
He could eventually get his diploma if he completes his final exams.
"He deserves to wear that cap and gown," Frost's step-father Stephan Johnson told the Associated Press.
Findlay High School requires students from other schools attending the prom to get a signature from their principal, which Frost did. But that tipped off his own school, which warned him of the dire consequences.
Frost attended with the blessing of Findlay's principal Craig Kupferberg, who boasts alumni such as Pittsburgh Steelers quarterback Ben Roethlisberger.
"We allow our students to invite guests as long as they check it out with the school," he told ABCNews.com.
"That's a small Christian school and I respect their values, but I don't happen to agree," Kupferberg said. "I don't see (dancing and rock music) as immoral acts."