underqualified as f_ck

Have you ever been in a situation where someone asks if you've thanked someone else for something he or she did while the three of you are in the same vicinity? 
I don't understand why people do that because:

1. If I did thank him/her already, are you implying that you think I'm an ungrateful and impolite little mother fucker who doesn't know how to thank someone? 

2. If I didn't thank him because I am an ungrateful and impolite little mother fucker, are you really putting me on the spot in front of that person? 

2a. And if I thank the person now, upon your question, won't he/she think it is fake and forced because IT TOTALLY IS?!

In conclusion,

Thank you.