Donald is in class. He raises his hand to get the teacher's attention again.

(T=teacher; D=Donald)
T: Yes, Donald. What do you want?
D: Excuse me, sir. May I go to the washroom?
T: But this is the third time in half an hour.
D: I know. But my mother made me eat a big breakfast this morning.
T: Why?
D: She said that if I eat a big breakfast, I will do better in my schoolwork.
T: But if you go to the toilet every ten minutes, you won't be able to do any work.
D: Uh... but if I don't go now, I'll do it in my pants.
T: Well, I guess if you've got to go, you've got to go.

pants(美)  trousers(英)  slacks休闲裤   shorts短裤
a pair of pants 一条裤子
greasy 油腻的   junk food
be in class 在上课   be in the class 在教室
make a good impression on
lavatory  washroom  W.C.(英)   latrime(军事用语)
qiuz 小考   a pot qiuz 抽考
do it in my pants 拉裤子(委婉)       When nature calls, we have to answer.