Lance Sanderson wants to bring a date to homecoming this weekend, just like he did last year. Except this time, Christian Brothers High School -- the all-boys Catholic prep school he attends in Memphis, Tennessee -- has told the senior no way.

Why?

"This Saturday is our homecoming, but I'm being told by my school that I may not be able to bring a date that I choose -- simply because he is a guy," Sanderson writes in a Change.org petition he started titled "Let Me Take My Date To Homecoming."

Sanderson, who has been out since his freshman year, continues, "When I first started to float the idea of bringing a same-sex date to homecoming, I was told that my school doesn't discriminate by a school official." He also says he was given permission to bring a male date to homecoming last year by an administrator who has since left the school.

"When that school official left over the summer, I was met with harsh opposition by my school," he explains. "One administrator told me that even though some people interpreted Pope Francis' teachings on the issue as meaning they should support same-sex couples, these people are, 'not the authority to which Christian Brothers High School is accountable.'"

According to NewNowNext, the school's policy explicitly states that "CBHS students may attend the dance by themselves, with other CBHS students, or with a girl from another school. For logistical reasons, boys from other schools may not attend." CBHS also issued a bulletin on its website with rules for Saturday's dance:

A letter posted on the school's website this week further defends its policies and references "developing a more pro-active outreach to gay students" as one of the goals for this school year. It goes on to mention the formation of a committee to develop an outreach program and train faculty members in their "counseling of gay students."

"[The committee] also had the task of creating a dance policy where ALL CBHS students could be included," the letter states. "This was not an easy task. The Homecoming Dance was changed to a format similar to our courtyard dances. No longer is it a date dance. The school has never let boys from other schools attend these dances as the mixing of boys from other schools in such an open atmosphere can cause problems."

Sanderson, however, believes the new policy was made explicitly in response to his previous requests to bring male dates from other schools.

Sanderson writes in his petition that CBHS has been issuing "daily announcements" across the school over the past week reminding students that they can't bring same-sex dates from other schools, which has made things even harder for him after what he described as four years of "a lot of homophobia."

"I just want to bring a date of my choice to homecoming like the rest of my friends and classmates," Sanderson writes. "I'm not asking for special treatment. I'm just asking for respect, and the chance to make my last homecoming a truly memorable experience."

At press time, the petition had received 11,140 signatures, a number Sanderson hopes will climb to 15,000. In the meantime, he's received plenty of social media support (SHONDA RHIMES!), and even inspired the tag #letlancedance.

The school's Code of Conduct states: "All CBHS students should feel safe, secure and accepted regardless of color, race, background, appearance, popularity, athletic ability, intelligence, personality, sexual orientation, religion or nationality."

A spokesperson from CBHS had not returned MTV News' request for comment at press time.