A vampire will seduce you with detached casualness, but a Lycan will fight to the death to keep you.
A vampire will seduce you with detached casualness and make you come until you scream. He will not stay with you, but will depart smiling, uncaring, having satisfied his own selfish desires and leaving you never wholly satisfied. You will beg to be his slave. He may accept you as such but will feel no responsibility for you. He will use other women and you will not care as long as he uses you. If you disobey him the punishment will be harsh and painful. If you die he will feel nothing but a vague sense of what-might-have-been.
If a Lycan loves you he will take you and ravage you with intense passion and make you come all night and leave you exhausted and satisfied. In return for your love and your unquestioning obedience he will protect you and cherish and love you forever, and he will fight to the death to keep you.
Lycans and vampires do not mix well.