Bad sex ed grade grade, Bad

XKC81579859

Three boys received their grades from their female sex education instructor. One got a D+, the second a D- and the third an F. "One day we should get her for this," said the first boy. "I agree. We’ll grab her..." said the second. "Yeah," said the third. "And then we'll kick her in the nuts!"

ssw_07

i don't quite understand this passage, it is a joke or something ?