Subscribe | UPI Odd Newsletter Subscribe SAN FRANCISCO, Oct. 11 (UPI) -- A group of San Francisco first-graders took a field trip to City Hall to attend the marriage of their lesbian teacher. The students from the18 Creative Arts Charter School students took a city bus to City Hall to toss rose petals and blow bubbles on their just-married teacher Erin Carder and her wife Kerri McCoy, the San Francisco Chronicle reported Saturday. Advertisement The newspaper reported that a parent came up with the idea for the field trip, which was a surprise for the teacher. The school's interim director Liz Jaroflow said the field trip was educational. "It really is what we call a teachable moment," Jaroflow said. The class junket drew criticism from proponents of Proposition 8, which would outlaw same-sex marriage in California. "It's just utterly unreasonable that a public school field trip would be to a same-sex wedding," said Chip White, spokesman for the Yes on 8 campaign. "This is overt indoctrination of children who are too young to have an understanding of its purpose."