here is one from my side not so funny though;

Student ask to the teacher in the practical class of Animal Husbandry, " Why male animals espically "bulls" make thier head toward the sky after smelling the genital of femaile "cow".

Teacher said" Animals are not much crazy for sex as human, they always observe the eniviornemnt by looking in the sky wether it is ok or not for having sex; if they fells the enviroment is ok they will have sex otherwise postpone thier date, that never happn in human"

Boys start to laugh girls ................