i agree some of your soon to be ex-husbands actions sound creepy. IMO maybe now would be a good time to ask your friends not to share any information regarding your spouse with you. Afterall he is a grown man. You certainly are not responsible for his actions.
His actions may be somewhat out of character and embarrassing to you, but they are HIS actions. You have no power over his conduct.
Just another thought, why are your friends accepting his calls? They could just as easily not answer the phone, or be direct and ask him to not contact them regarding you.
Sounds to me as if your friends enjoy this drama a little bit too much.......
Take care of you, wishing you all good things.............