Dropping Panties

I don't know about you but I often re-wear clothing.  If it doesn't get dirty why not?  We know you do so just fess up now.  And like me, you probably have a piece of furniture in your room that you lay said clothing over to prevent them from getting wrinkly before your next wearing.  I have a straight back chair.  Currently it has a sweat shirt, yoga pants, and a bra laying neatly across it.

On Saturday I wore a pair of jeans out to dinner.  They didn't get dirty, so I carefully laid them out over the chair for wrinkle free safekeeping. On Sunday I put on the already once worn pair of jeans to run my errands.  I went to Walmart, Target, and got gas.  I came home, put the cold groceries away and then took one of the dogs on a walk.  Upon returning home and putting away the remaining groceries I felt a little tickle on my leg.  I began to panic a little bit thinking there may be some sort of insect or rodent in my pants (in hindsight the likelihood of a rodent in my pants was very slim).  I shook out my pants leg with vigor hoping to kill whatever was in there.  And then a pair of underwear fell out of my pants leg.  I had shook with a vengeance and killed a pair of Victoria Secret black thongs.  WTF?!
A,  Had I worn the pants all day with the underwear stuck in the leg and not noticed?
B.  Had I worn the pants on two separate occasions and not felt the hitchhiking panties?
Either they are really sneaky or I apparently have limited feeling in my legs.  At least I didn't walk around all day with a pair of panties stuck on the back of my sweater or in a bunch.