pain full love

there is a guy who i love him.... bt he had already a girlfriend... there are broke up now.... he knows dat i love him... he also said that he wants me..if i be with him he feels happy..... he said he had some feeling .... but he was afraid that if he start a new life with me.... then what happen to his ex-girl frnd ... if she come backs for him what he has to do... he dont to hurt me... he dnt wnt to hurt her.... but i am loving him my childhood... i am unable to forget him.... what to do...