Sometimes, despite a girl's best efforts, the guy she's crushing on just isn't interested. In her determined attempts to get his attention, she quickly becomes annoying, which often leads him to ignore or avoid her. While a true gentleman never wants to be rude, failing to confront the problem will only prolong it. When you find yourself in a situation like this, the best thing you can do -- for your own sake and hers -- is to be direct, upfront and honest.
Make your limits clear. If she constantly approaches you on lunch or when she spots you at the mall, for example, politely say, "I'm sorry but I don't have time to chat." If she messages or calls you despite getting no replies, respond with a plain statement such as, "Let's keep our conversations limited to class projects during school hours." Of course, a simple "I'm sorry, but I'm not interested" sends the message home in a clear and polite way.
Set clear boundaries and make them known. This step is especially important if the girl who's bugging you is a classmate, coworker or anyone else you might see regularly or have to work cooperatively with, or someone who's ignoring your limits. Clearly and directly state your boundaries in simple terms. Say, for example, "If you continue to ask me personal questions, I am going to request a different lab partner" or "I need you to stop calling my phone or I will have to make a complaint."
Limit her ability to pester you. Keep your personal information private. Don't post or share your phone number, address or email on websites or other public places.
Talk to a teacher, manager, family member or other trusted person if the girl still continues to pester you. Determine whether her behavior can be classified as stalking or another form of harassment. Go to the administration or the police if your requests for her to leave you alone go ignored.