Girls are yor feet ticklish? if so has anyone ever tickled your feet whitch drove you crazy?

The other day i went over to my girl friends house and seen her pin her sister down and tickle her feet to the point i thought her sister was going to lose her mind. I never her anyone laugh so load and for so long and beg like i have never heard beging before. Has anthing like this ever happen you or seen it happen to others. please explain.