This happened with my cousin. She is a lecturer of sociology in a government college.

Someone sent a match of a boy who was working as a PO in SBI. The family seemed nice so my family invited them for lunch. Their family was simple and all was going well. Suddenly topic of education came up. Boy's father started telling tales of his overachieving son and how he cracked most prestigious job in India in his first attempt. He told us how his son won laurels for his school in Olympiads and Quizzes.

My cousin's brother( an IITian) asked him innocently that why he choose to become a PO instead of doing engineering(after all the boy was child prodigy as per his father's)? Boy's father became furious at this question. He started cursing engineering. He explained how engineers are wasting Indian government's money by working for multinational companies. He told us how brave his son is for not following the crowd. According to him, government job is the best(maybe that was the reason that they decided to visit my cousin).

After a little chit chat they decided to give prospective bride and groom some privacy and left the room. Now there were only three people in the room. The guy started telling about his hobbies and his favorite subjects(yeah he did that). He told my cousin that maths is his favorite subject although many students dreaded maths.

Guy: My family give ultimate importance to education. I want a girl that could do the same. I don't want my children to be bad in studies.
my cousin: hmm.
Guy: Which is your favorite subject.
my cousin: maths
guy(a little confused) : But you are a teacher of sociology, right? How come your favorite subject is maths?
my cousin: My undergrad subjects were sociology,economics and maths.
guy(still not convinced) : I will ask you a simple question. Let me check your maths. What is the differentiation of SinX?
my cousin: I am not good in calculus but I think its CosX.
guy: actually its CosX dx. Many brilliant students fail to answer it correctly.
my cousin(a little pissed, trying to keep smiling) : oh I told you I am not good at calculus.
Guy: Girls are usually bad at maths, no problem. btw I am impressed that you gave partially correct answer to my question. Didn't expected that from an arts major. Why did you took maths in undergrad?
my cousin(now decided to teach this guy a lesson): We use a lot of maths in sociology. My PhD work was based on mathematical modelling. Its good that your favorite subject is maths. I have some doubts which I think you can clear.
Guy(somewhat tensed) : You can ask me anything but right now we have some other important stuff to discuss.
my cousin: No, it will just take a second. (She grabbed a notepad and started writing some random equations). I would be highly obliged if you could solve these set of equations.
Guy(now petrified) : Sure but my dad and mom are waiting. (Then he calls for his dad)

Now his parents arrived. They were confused as my cousin was with notepad with some maths questions on it. When he came to know about it he asked his son to solve that. The guy was now really screwed up. He told his dad that he couldn't solve this. Interesting thing is that he never saw that equations.

Feeling somewhat insulted they decided to leave and told us that they need some time to decide. They never called. When my family members came to know about this they had a great laugh. Poor chap, I still feel sorry for him. If he is reading this I want to tell him that my cousin just scribbled some random equations on that notepad.