Someone who is able to stalk a person at work, usually after hooking up, since both work within the same company. Usually a work IM status will alert one of the characters that the other is in a meeting, out of the office, at lunch, etc.
Milosh: Sarah has not come by my desk at all since we made out at the office Memorial Day party last weekend. She must hate me.
Billy: Maybe she is out of the office this week.
Milosh: No, I know she is here. Her work IM status says she is in a meeting in the conference room until 2 pm.
Billy: Dude, you are totally a WOLKER!