Man, I am having similar problems.

For 6 months a female co-worker keeps on texting and calling me. When she has the chance, she will sneak after me to the kitchen and block my exit, demanding to talk or kiss. She will openly flirt with me in the office, even though I have told her to stop. When I stopped taking her private calls, she just stated calling me from the company number, which I cannot ignore. 2 weeks ago, she arranged to switch places with a coworker, so our desks are now right next each other.

I am single and she is married. I must have rejected her 100 times over the last 6 months. I had a promotion talk with my boss, where they basically said the only negative thing holding me back was not talking properly to this co-worker - cause she drives me out of my fucking mind.

I'm at the limit of crap I am willing to go through to spare her dignity, marrige and job. The only reason I let it get this far, is because I feel guilty for returning the flirt the first couple of weeks, until she started pouring on all the crazy.