Imagine you meet somebody and have lunch together. They seem like a very nice person and they enjoy their time with you as well. Lunch goes well so you plan to continue on into the night and grab an ice cream. She phones her roommate and tells her that she has to bail on plans tonight because she's got to cram for a meeting in the morning. You know full well she's lying and hanging out with you but you let it slide because she's cute, and we've all done this before.
Things flourish over the next couple of months and you keep hearing these little white lies in order to get out of tough situations. You may not be surprised if you someday find her being dishonest with you as she displayed her character in front of you for you to see on several occasions.