No one ever does anything for no reason... maybe she is not happy - found someone who made her happy. maybe she is frustrated "se.....ly" and found someone who let her release her frustrations.. or maybe she just found some one who gave her the time of day and took the time to listen to her...
Could be any of the above or then again it could be she just wanted something else...
Dont be too quick to judge just cause its a woman... if it was a man am sure it would be a different case !!!!