Here's what happened, apparently:
On the bus to Tynan Elementary School in Boston, seven-year-old Mark Curran was approached by a bully who wished to take his gloves. The bully began to strangle young Mark, who responded by kicking the bully in the balls. According to CBS Boston:
[Mark's mother, Tasha] Lynch described a phone call she received from the school explaining that the case will be treated like sexual harassment, due to what it considers inappropriate touching.
“‘Your son kicked a little boy in the testicles. We call that sexual harassment,'” Lynch said the school told her.
She said she's been asked to attend a disciplinary hearing at the school Monday.
… “He's 7 years old. He doesn't know anything about sexual harassment,” [Lynch] said.
Of course, the other boy's side of the story has yet to be told.