People may not always tell you how they feel about you, but they will always show you. Pay attention
Flirtation usually refers to attempts to attract a romantic interest, showing the person great interest and trying to be as appealing as possible. Some people engage in a flirtation very lightly as a way to pass the time, without any real intention of taking the friendship any further. For others a flirtation is viewed much more seriously, and the act may take on a very big significance.