If u want him to propose to u then what i'll suggest u to do is to make him feel that u have the same feelings for him by not telling him directly....i mean behave like he's ur boyfriend....that way he'll get a feeling that may be u are the girl he had been looking for...ensure him that he'll find himself in a safe relationship n that u will never dump ( make him feel all this indirectly...u're behaviour towards him, u're expressions, gestures..u know!these are what counts )...he's actually worried..he doesn't want the same thing to happen to him again...n it's upto u to make him feel that u have true feelings for him. hope u get what i mean