Looking too long at someone may seem to be rude and aggressive. But things are different when it comes to stare at the opposite sex. If a man glances at a woman for more than 10 seconds and refuses to avert his gaze, his intentions are obvious, that is, he wishes to attract her attention, to make her understand that he is admiring her.
However, the normal eye contact for two people engaged in conversation is that the speaker will only look at the listener from time to time, in order to make sure that the listener does pay attention to what the former is speaking, to tell him that he is attentive.
If a speaker looks at you continuously when speaking, as if he tries to dominate you, you will feel disconcerted. A poor liar usually exposes himself by looking too long at the victim, since he believes in the false idea that to look straight in the eye is a sign of honest communication. Quite the contrary.