NEW YORK - Gotta get a date, girls.

Administrators at St. Peter's Girls High School have mandated that juniors wanting to attend the May 22 prom each must be escorted by a male companion.

Even students unaffected by the sudden policy change at the Staten Island school said they don't understand the couples-only rule.

"I just heard about it now; they can't go unless they have a date," said senior Deanna Stropoli, 17, of Dongan Hills, who is attending the senior prom with a boyfriend. "I think it's kind of messed-up. Some people aren't going to be able to go."

There is no such restriction on seniors.

School interim principal Florence Bricker wouldn't comment this week on the policy, which is a change from previous years, and St. Peter's R.C. Church Monsignor James Dorney said it was strictly a school matter.

Representatives for other Staten Island all-girls high schools said they have no such policy for their junior proms.

The city Department of Education doesn't have a formal policy governing proms at public schools, but a spokeswoman said this week that a dates-only dance would be "highly unlikely."

"It wouldn't happen in public schools - everyone's invited," said department spokeswoman Margie Feinberg, although she said prom arrangements are up to each school.

St. Peter's always has declined to divulge its student numbers, but the total is thought to be less than 300. The couples-only policy might have been enacted with an eye to boosting attendance at the prom.

"I think it's crazy," said Lisa Mulea, of Staten Island, as she picked up her daughter, a freshman, at the school. "If a girl wants to go, if they go to the school, they should be able to go."