Updated

Rosanne Strott says she was not trying to make a political statement. She just wanted to invite a close friend to Friday night's prom at Bishop Feehan High School.

The problem was, that friend was a woman. Catholic Diocese officials barred the same-sex couple from attending the prom together.

Strott told The Boston Globe that school administrators are discriminating against her because she is openly bisexual.

"I was just trying to bring a friend and have fun," she said. "I decided that if I couldn't go with who I wanted, I wasn't going to take anyone at all."

Even though Strott bought tickets and her friend paid for a spaghetti-strap dress and brown pumps that Macy's won't let her return, the 18-year-old senior said she will go stag to the "007: Diamonds are Forever" theme prom. She planned to wear an orange and yellow dress and Swarovski crystal necklace.

Administrators said the same-sex couples ban is intended to keep the high school proms traditional.

"We're not looking for trouble at our prom," said George A. Milot, superintendent of schools in the Diocese of Fall River. "Having boys bring boys or girls bring girls opens the door to all kinds of scenarios that could lead to problems. We're not willing to open the door."

Sarah Wunsch, a staff attorney for the American Civil Liberties Union of Massachusetts, told the newspaper that a same-sex couples ban would be illegal at public schools or even secular private schools.

She said state protects against discrimination on the basis of sexual orientation, but diocesan schools are not subject to the rules as religious institutions.

Ryan Palanza, the student head of the school's prom committee, said he wished Strott could bring her date.

"We have to adhere to the diocese's rules," he said. "This is just a diocese thing."