I was spanked at school as late as 15. I have no doubt that the teacher got some sort of sexual thrill out of it as he was known (among the students) as only spanking girls and for pulling up our skirts. No, I never told my parents because I was afraid that they would be more concerned over my being bad and would get another spanking at home. At the time I was a sophomore in high school and I talked my parents into allowing me to go to the public high school, which I loved. Unfortunately, we moved cross-country 6 months later and I was back in a Christian school again, but at least I avoided spankings as a junior and senior in high school.
Sexual thrill? I have no doubt about that.