Summarize the following:
If you truly want the behavior to stop, do not laugh or give "come hither" looks. And be careful how you use body language to confuse the matter, as some people can get mixed signals and assume there is more that you're simply too shy to vocalize. In one infamous case, an investment manager accused his date in an email rant of giving him reason to believe they'd have a second date, based simply on her hair twirling, constant eye contact and being nice to him, so he felt petulant when she refused to see him again! While that's a particularly awkward case, body language is something over which you have control, such as: Turn your head or look away when the other person begins to flirt or uses flirtatious body language. For example, if he or she comments on your appearance, look away and do not respond. Move away from the other person if he or she touches you. If the other person grabs your hand or puts his or her arm around your shoulders, back off and move away. It's fine (in fact probably desirable) to tell them not to touch you again too, saying you don't like it. Remain civil. Never lash out with nasty comments or mean remarks; it may not only encourage the behavior but can make an uncomfortable situation even worse. If you are a normally flirtatious person with everyone you meet, try to tone it down around this person because they may be unable to distinguish the fact that you act this way toward everyone and not just toward them. Alternatively, have a good friend take them aside and explain that this is the way you behave with everyone, so as to burst their balloon early on. If you are at an office party, social event or bar, politely excuse yourself and leave. Go and talk to other people, making it difficult for this person to get close to you again. In a professional context, you can draw the line using work as the excuse. Tell them that you (or they) have to leave because you have work to do, a meeting to attend, a deadline to meet, etc. If there is a habit of this person "hanging about", you'll need to get more specific and let them know that you don't appreciate having your work time interrupted so frequently. If your friend or peer witnesses the behavior and seems to egg it on, discuss your feelings and let him or her know you want to diffuse the situation, not encourage it. Hopefully next time you are together and the flirting begins, your friend has your back and you can both provide a non-reactive response.
Do not ever flirt back. Walk away from the situation. Discuss the behavior with a close friend or work colleague.