People Try to Play around with your emotions and their could be several reasons behind it
1. They Are Jealous
2. Also when they know that you dont have a control on your emotions (sadistic)
3. Some do it unknowingly (not intentional)........the list doesnt end here......
Emotional abuse is still abuse.
the selfish 'i want, what i want, when i want it" attitude.
if a guy wants to sleep with three women...and he wants you, but he knows he has to lie about something to get you, then he will do that.
The answer to any why question is generally speculative, but can still be answered in broad terms. To answer your question, I feel I have enough information and some intuition to supply a direction in which an answer could be found. There are several personality disorders in which this type of maladaptive behavior manifests. This above mentioned trait is seen in Passive Aggressive Personality, Borderline Personality, Antisocial Personality Disorder, Narcissistic Personality Disorder, among other formal personality disorders. As with most people, there are a mixture of personality traits that are a working part of ones being. Generally speaking, the person is aware that this behavior is abusive and that is this persons intent. Alcohol and drug abuse may trigger such traits to be more prominent.
They do it for control. Some are just sick in the head like that. I consider it very abusive.