One of my Yorkies is a semi-obsessive licker. The first one I had, Mr Pippin was even worse. Mine have never liked to lick fabric, but like to like any exposed skin, and before bed time is THE time to get some licks in.
We do let Ms Daisy lick our arms for a minute before we tell her to "go to sleep." She actually is pretty good at obeying this command, and she will stop the licking. Sometimes she will get in a licking contest, kissing her "brother", but he will only put up with so much of that before he stops that game.
I think the spazzier of more "high strung" your Yorkie (any dog really), the more they are prone to this obsessive licking behavior.