And their ages are …?
If we are talking teens and/or young “adults,” say in their early 20s, don’t forget the immaturity factor. If he drives a loud vehicle and/or with big tires that immaturity factor plays a bigger part. 
If these friends are older, he’s got problems he has yet to address.
Having said that, Audrey Levins’ advice is probably the best in this thread.
Look how much of this is something that she can control! She can still carry her cell phone and she should let him know that it will be turned OFF unless she needs to make a call. When he calls at work and she doesn’t want to talk, she should tell him so, give him a sweet “goodbye” and hang up. She can refuse to give him any details about her time away, but just a general comment would be kind. (“We just hung out at Kelly’s bar.”)Going out with friends – no matter who they are – is her decision to make. She seems to be giving away too much of her power. If I were she, I would write down what my boundaries are and what the consequences are if he refuses to respect her decisions and them give him a copy. She can also point out that he has the right to set boundaries about himself too.
But don’t you dare suggest this unless she has asked for your advice!
Yea, if you come barging in (her view!) with all kinds of unsolicited advice, you might even drive her closer to him. She’ll probably, at the least, feel very defensive, and thus less likely to listen to what you’re saying.
thanks for all the replies, i’d sent her this url.
they’re in their early twenties. i think we agreed time is what they need, so here’s hoping everything works out for the best in the coming months…
shijinn, some people like it. I don’t know if you watch the new show, Northshore, which is a reality show based on surfing, but there is a possessive guy in it & his wife just loves it…
shijinn, personally, I think sending her this url is/was a really bad idea. The odds are she’ll show him, he’ll read what you’ve said (which is clearly very one-sided, even if it’s entirely correct), and be rather upset with her for spreading their relationship out amongst alot of strangers where he’s portrayed as a bad guy. And there goes your friendship with her.
I stick with my original advice: butt out.