OK, let`s determine who said what. :)
I said:
Yes, that`s what my students use to say when I am pulling their legs.
never mind the mistake, I used the phrase with the full awareness of its meaning.
Then you wrote:
Meaning you must be joking or making something up not being serious.
that is why I said it was mysterious because I didn`t know why you did it.
I was giving you the definition/meaning of pulling someone's leg and not legs.
Whether leg or legs, I presume it always means the same, doesn`t it? :) It is just the matter of one silly "s" which doesn`t thoroughly reverse the meaning, right? So, my surprise was quite justified.
Well, after we nicely resolved the issue, you too have a blessed day but we are going to read each other more often today as my PC is on all the time and I come back every 30 minutes to see what is going on. I am finishing the hall in our summer house.