What kind of a person would lie in this manner?

I am just wondering, what kind of a person would tell a woman he likes her and kisses/holds her, and the next day dumps her with an utter blank and emotionless face for the reason he doesn’t like her much/enough.

Who does this? I am having disbelief that anyone in their right mind would be this disgusting and deceiving.

I personally couldn’t go on living if I have acted like this toward someone who opened their heart immensely to me.