worse than the bloodsucker

Sarah was worse than the bloodsucker... time and hindsight is 20/20.  She pretended to be concerned about me and what the bloodsucker was doing to me...  all the while getting info to talk the bloodsucker and form a relationship with her. She even shared a 'secret' to help me feel better about what i was going through in order to get more info.  How could a 'friend' do this  - can love (or lust) for another lead you to break off all relationships with people you care about?  Well in her ex husband's case and guess yes it had to be... but a friend?  Yes because i guess the bloodsucker couldn't let me go at that time because i was the first person who had rejected her in her whole life and Sarah wanted to help me and get out of her way...