Prom a constitutional right?

According to the ACLU a high school student in Mississippi had her constitutional rights violated when she was denied a ticket for prom. The school denied her tickets after she told them she planned to go in drag with a member of the same sex. The schools prom policies state that students can only bring dates of the opposite sex. Now before you get all worked up thinking this is an anti gay rule the purpose of this policy is to prevent students from bringing friends of the same sex who otherwise don't qualify. i.e. underclassmen or students from another school. apparently the prior applies to this situation because the date was a student at the school but couldn't get her own ticket. Well, the ACLU went after the school board and demanded special concessions for gays and lesbians... The schools response... No, and to avoid more harassment the school board canceled prom this year. Prom a constitutional right?