Only talk to E the first time you ever get to the beach. Gotta do it right first time or it dont work
First say 'thats cool. mind if i chill with you?' Then only ask about him and lily, no vampire related questions(this is important). Then say maybe i can look into this. E will then tell you his name is E, bid him farewell and you should have the quest
Note that you gotta do it the first time you ever speak to him. This is only a rough guideline of what to say and it should work