Wanting some advice to help

My friend jill was dating a guy, who then cheated on her, after 12 months of being with this woman he got in touch with jill again, they started talking, this woman he cheated with basically stole from him, blamed her son for stealing from him to where he had to buy a safe and lock his valuables up. He told all his friends what she had done to him. Now she finds out that he is back with her and a mutual friend told her even more disgusting things she did while with him, like doing sexual things for pills, got her uncle to video tape her and him having a 3some with a friend, he has not told her he is back with her, he has said nothing for weeks to her. The woman has posted stuff on her fb basically implying they are together but he has said nothing at all. The mutual friend posted on his wall congrats he was back with this other woman, which he removed and got the woman to ring and tell the friend not to post anything on his wall containing to them being back together till he told jill, this woman also said he is thinking of how to let jill down easy, so she sent him a message basically opening the door for him to tell her, which he has not replied, what we are all confused about is why he is keeping jill on his fb and why he is not telling her he is back with this woman, he has had ample opportunity to tell her and he would have to know that jill knows, so yeah why on earth would he still want her on fb.

There are multiple possibilities. He probably wants to be with Jill in the long term and is not sure of this other woman? The other woman could be blackmailing him with pics or things? Difficult to say without knowing the full case properly.

She has tried that, but he won't pick up the phone, this is why she messaged his friend on fb and got told all this stuff, this is why we are all confused as to why he hasn't told her he is back with this woman and hiding he is