Educators said they had no choice, but thousands have protested the move through Facebook groups and petitions demanding that Michael Griffin be rehired at Holy Ghost Preparatory School. Some alumni have pledged to withhold financial support.
Caught in the middle are people who say Griffin should have known he was jeopardizing his job by publicizing his plan to wed, as well as those who worry the negative publicity is unfairly labeling the Bensalem school as intolerant.
"It is a shame that the students and faculty are being painted a certain way, because it is apparent with the amount of support Mr. Griffin has received, this is not the popular mentality," said 2012 alum Rob Blackwell.
The case started last week when Griffin informed the principal, via email, that he would be late to a staff meeting because he was getting a marriage license. Griffin and his partner live in Mount Laurel, N.J., a state where gay marriage is legal.
Same-sex unions are not sanctioned under church teachings, which Griffin was required to uphold as a condition of his employment. School officials say they respected Griffin's private life until his email forced the issue.
"All of us, including Mr. Griffin, understood that his decision would place him in violation of his contract," according to a statement from the school.
Griffin, a 35-year-old Holy Ghost alum, counters that he didn't hide his relationship with his longtime partner, whom he joined in a civil union in 2008. Griffin did not respond to requests for comment left by The Associated Press, but he told The Philadelphia Inquirer that his partner even attended school functions.
"Clearly, we were a couple. We both wear rings, and we were together," Griffin said. "The alums and donors, they could all see that."
After his termination Dec. 6, the criticism came fast and furious. One protest letter lambasted the school for "this apparent assault on diversity, this closemindedness and this devotion to doctrine when change is happening all around you."
"Griffin deserves to be congratulated on his upcoming nuptials, not banished for making the news public," said the letter, signed by nearly 100 alums, parents and former staff members.
Blackwell, who signed the letter, described Griffin as "really a positive influence on the Holy Ghost community" and said the firing goes against the school's philosophy about caring for all people. He also worried about the effect on current students.
"Students who are gay would probably not feel like it's the same accepting community it once was," Blackwell said.
School officials portray the firing as a purely contractual issue that, if not addressed, could lead to a slippery slope. They've held several meetings with students and staff over the past week to explain the decision and mend fences.
Rita Schwartz, president of a local Catholic teachers union, described the environment at church schools as "don't ask, don't tell." Though she does not represent staff at Holy Ghost, Schwartz said all Catholic schools require faculty to adhere to church morals - and that goes for heterosexuals, too.
Schwartz said she's seen straight Catholic teachers lose their jobs for remarrying without getting their previous marriage annulled.
"When you sign on to work in a Catholic school ... there are certain things that you can't do," she said.
That raises the question of why Griffin told the principal at all. Griffin, who taught Spanish and French there for 12 years, noted his partner's presence at a fundraiser might easily have qualified as grounds for dismissal.
"To me, that was much more public than me emailing the principal," Griffin told the Inquirer. "That's why it's sort of a shock to me."