He is clearly not telling the whole truth but I get it. if romeo teleported to where juliet reincarnated to this would be the same result. enemies but fell in love. one died, the other chased them to the other world. but she forgot about him. the new incarnation doesn't remember. can't just tell her everything, so you revert to playing the old façade you had when you met in the previous life. but the true intentions still remain hidden beneath it all.