Seductive Twins

Evangeline Brooks only 22 years old doesn't want to live with her rich parents anymore. She wanted to be young,wild and free with no interruptions. Evangeline gets that opportunity when she meets Andrew Richards at a club. After long meaningless sex Evangeline doesn't see Andrew again until she sees him at a park but he doesn't remember her . It was like he was a complete different person .
Could it be he has a personality disorder or he has a twin?
What happens when she has sex with them both but then gets pregnant ? Whose the father ?