The photographs taken earlier this fall were widely circulated via e-mail on campus and appeared on at least one other Internet site.
By featuring the pictures on his personal Web site hosted through the school’s server, the photographer violated the school’s code of student conduct, sexual harassment policy and policy on acceptable uses of electronic resources, the university said in the memos.
"If somebody chooses to make a public spectacle of themselves, then they get what goes with that," Andrew Geier told the school newspaper.
Since the pair was visible in the window, Geier said, the photos were taken in public and are completely legal.
Geier did not immediately return a telephone message left by The Associated Press on Wednesday.
A professor at the prestigious university agreed with Geier.
"The student took a photograph of a public event. That is protected expression," said professor Alan Charles Kors.
Penn spokeswoman Lori Doyle said Wednesday that she could not discuss the case.
"The disciplinary process is supposed to be completely confidential," Doyle said. "We’re hopeful that this matter can be resolved quickly and satisfactorily between all parties involved."
Penn will hold a hearing in this matter on Thursday.
Schools: University of Pennsylvania