WATCH: Iowa Catholic School Students Protest Denial of Job to Gay Teacher

More than 150 students and alumni of a Des Moines-area Catholic high school demonstrated Wednesday in protest of the school's decision not to offer a full-time job to a substitute teacher because he's gay.

The teacher, Tyler McCubbin, is engaged to another man, The Des Moines Register reports. He recently applied for a job at Dowling Catholic High School in West Des Moines, where he has worked as a substitute. But he wasn't offered the job "owing to a personal situation that is at odds with Church teaching," says a letter sent to Dowling parents by Luvern Gubbels, the superintendent of Des Moines Catholic Schools.

The letter does not mention McCubbin by name or his relationship, but a statement from the Diocese of Des Moines mentions that a "social media scan" revealed that the applicant in question "is in a same-sex relationship and is engaged." He no longer subs at the school, a diocesan spokeswoman told the Register.

The students walked out of class Wednesday and prayed in the rain with alums. "I just want the community to know that this is a really important topic, and that just because our school officials or diocesan leaders might have made this decision, it does not directly reflect what we believe as students," said Grace Mumm, a 16-year-old Dowling sophomore, according to the Register.

One alumna, Gigi Filer, who is also the parent of a Dowling freshman, said she thinks school administrators are "cherry-picking the Catholic doctrine," the Register reports.

"It's a slippery slope," she added. "Where do we draw the line?"

Another alum, Andrea Cook, who will have a child entering Dowling in the fall, said she worries the school will lose good job candidates through discrimination. "I want Dowling to stay a strong school," she told the Register.

The students had planned and received permission for the walkout and will not be disciplined, a Dowling spokeswoman said.

The diocesan statement, from Bishop Richard Pates, notes that Des Moines Catholic Schools contracts "contains specific language that outline the code of conduct in accord with long accepted Church teaching" and that "it is our expectation that staff and teachers support our moral beliefs as they are the models of our Catholic faith." There have been several cases around the nation of staff at Catholic churches and schools being fired or not offered jobs because they are engaged or married to a same-sex partner.

Iowa law prohibits discrimination based on sexual orientation but exempts religious institutions. "Just in terms of employment discrimination laws, religious institutions can in fact discriminate on the basis of sexual orientation," Paul Gowder, associate law professor at the University of Iowa, told the Register. "Whether that's a good idea or not is another question entirely."

Watch a video report below.