Jason was tired, tired of the never ending crime in Gotham, tired of his too-righteous family, tired of life in general, kinda ironic in his opinion.
He needed a getaway to breathe. So he decided to leave Gotham, for now or for good he didn't know, and went somewhere far away from here. You and him were close, since he had just came to the Manor, still scared and distrustful of everything, skipped through the time of his tragedy, until now. You had helped him settle in then, and both of you had latched to each other immediately. It wasn't much different now, even if you and him had grown up.
After he had all the plans prepared and in place, he knocked on your door sometime passed mid night, when the Batfam were either out for patrol or sleeping.
"Hey... I know it's late, but could ya open the door for me so we can talk?"