Well, generally speaking, you are not supposed to share eyeliner with someone else. Or it can infect your eyes, and make your eyes become pink eyes. As we know that eyeliners are made of chemicals, it can be easy invaded by some other irritants. And if you share them with some else, it can increase the risk of being infected. And then it can lead to pink eyes. As we know that pink eyes is an infection of the eye or eyes which can lead to redness, itching, irritation, and a characteristic creamy discharge in your eyes. In other words, by sharing eyeliners, they can carry many bacteria, so that it can lead to infection to your eyes, even the pink eyes, for our eyes are very sensitive to the infection. Anyway, you should not always wear eyeliners, and also should not share them with others. Besides, you can drop some eye drops in your eyes, and it can relieve your symptom. Anyway, just be careful about it.