I bet many of you have heard, "I'm sorry". The words might have been spit at you. They might have come with tears. They might have come with the additional plea that "you have to believe me."
But I'm here to tell you something about those words. They are meaningless if they are not accompanied by a genuine acknowledgement of the pain he caused you (and the whole family, whether or not they're aware of what he did). They are meaningless if they are not accompanied by a plan to make amends.
That's where a lot of these "I'm sorry"s fall apart.
When you ask him to accompany you to therapy.
When you ask for access to his phone, his computer, his e-mail history.
When you ask him to stop going out with the boys, to stop drinking, to stop flirting.
When you ask him to unfriend ex-girlfriends on Facebook.
In other words, if he isn't backing up his "I'm sorry" with full-throated support of your needs and absolute respect for your boundaries, then his "I'm sorry" isn't worth a damn.
Which means neither is he.