He wore only a trench coat, a Richard Nixon mask and tennis shoes.

In the past two weeks, two auditorium-sized ISU classes have been interrupted by a man streaking and exposing his genitals to them.

A man wearing a trench coat and a rubber Richard Nixon mask entered a Sociology 134 classroom through the north door of the Curtiss Hall auditorium at about 10 a.m. on Feb. 10, said Brent Bruton, professor of sociology.

The man ran from the north side of the stage to the south end, exposing his genitals to roughly 400 students and yelled words few could understand, Bruton said.

“Our professor just stood there,” said Kristi Primus, a student in the class and sophomore in pre-journalism and mass communication. “Our class was just dying laughing.”

The whole event took place in less than 10 seconds.

After the class regained its composure, Bruton began his lecture on social deviance, using the streaker as an example.

“I’ve learned to take these things in stride,” Bruton said.

On Friday, a man entered Lush Auditorium in Kildee Hall with a black trench coat and rubber mask minutes after the class had started a meteorology exam, said Erik Triggs, freshman in pre-business.

“I looked up and was a little scared at first,” Triggs said. “I thought he might start shooting or something.”

The man opened his trench coat, exposed his genitals, danced around and ran from one door to the other yelling “I am El Ni¤o,” Triggs said. The teaching assistant chased after the man as he exited the room, he said.

Seconds later, the teaching assistant returned with the black trench coat, threw it on the floor, and the class cheered, he said. The teaching assistant reported to the class the man fell into the snow as he grabbed at the coat, Triggs said.

The class is taught by Cinzia Cervato, assistant professor of geological and atmospheric sciences, who was out of town at the time and said she was unaware of the incident with the streaker.

ISU Police Capt. Gene Deisinger said only one case of indecent exposure has been reported this month.

Deisinger said on Dec. 10, 2003, a man entered the Molecular Biology Building and exposed himself. The man was described as college age, with a black trench coat and a rubber mask.

If arrested, the man could be charged with indecent exposure and disorderly conduct, he said.

In the more than 30 years he’s taught at Iowa State, Bruton said he has witnessed many strange events, including streaking.

Years ago, a student whom Bruton knew entered his classroom with a trench coat and exposed himself with his back to the class. During another lecture, a man ran toward Bruton and tossed a pie at his face. Bruton didn’t press charges or identify the students.