A group of San Francisco first-graders took an unusual field trip to City Hall on Friday to toss rose petals on their just-married lesbian teacher – putting the public school children at the center of a fierce election battle over the fate of same-sex marriage.

The 18 Creative Arts Charter School students took a Muni bus and walked a block at noon to toss rose petals and blow bubbles on their just-married teacher Erin Carder and her wife Kerri McCoy, giggling and squealing as they mobbed their teacher with hugs.

Mayor Gavin Newsom, a friend of a friend, officiated.

A parent came up with the idea for the field trip – a surprise for the teacher on her wedding day.