do you get the under the boob sneak attack? i hate that.
anyway, it's a combination of wanting to feel textures (i notice her making the same hand motions when she's sitting on a plushy blanket or being held by someone in an interesting shirt) and a sort of over-stimulation, over-tired release, because it's worse when she is trying to fall asleep (or should be falling asleep).
i try to wear a tank under my shirt, shirt comes up, tank goes down, and she can clutch, pinch etc the fabric, not me. when i sense a certain amount of 'franticness' to the pinching and grabbing, it's a sign she's overstimulated, so i tend to straighten her bottom arm and clamp it under my elbow, hold down her legs with my other arm and hold her top hand with mine. generally the little fingers relax and stop moving and she usually falls asleep or at least calms down.
when i'm in the mood, (and her nails have been recently trimmed!) i don't mind it so much... we even play games, but yeah, i almost always try to redirect to holding the fabric of my shirt, or holding my hand.
