Wait until she's barefoot and somebody else is sitting next to her. When neither of them are looking, tickle her foot and then leave quickly. She'll think the person sitting next to her did it.
"Sneaking" implies furtive, plausible deniability, which is underhanded and borderline creepy. Do it, and be confident, playful, and fun about it - preferrably, as GQGuy said, in an atmosphere where tickling wouldn't be out of place.
No. Because then she'll ask the somebody else, "Did you do that?", and they'll say no, and then they both will know it was you, and you'll be the sneaky tickler that makes people uncomfortable.
"Sneaking" implies furtive, plausible deniability, which is underhanded and borderline creepy. Do it, and be confident, playful, and fun about it - preferrably, as GQGuy said, in an atmosphere where tickling wouldn't be out of place.
No. Because then she'll ask the somebody else, "Did you do that?", and they'll say no, and then they both will know it was you, and you'll be the sneaky tickler that makes people uncomfortable.