A friend.
No it is not the case that men are cheating if they call their old girl friend. It might be the fact that he treats her as a friend. It can totally be that case, do not take that negatively.
Call the cops.
The dream only means that something has brought that old friend to mind; it might have been a snippet of music, a familiar place or even an odor. This question is posted during the holiday season, so the memory of the friend could be associated with the holidays. However the dream was triggered, it provides an excellent excuse to make a phone call and get back in touch with that old friend.
She wants him back
if you dont have feelings about him like if you dont want to date him ten ask him nicely if he can back off
it depends on what movie you want to see
Yes, it is correct, but rather literary, not to say old-fashioned in today's idiomatic English. In normal speech, the phrase is "You want him to be your friend" or "you want to be friends with him."
Call the cops!
You call him and say hey do you want to do something?
In Chinese, old friend is translated as "老朋友" (lǎo péngyǒu).
You can also make one. My friend has one if you want it but I am not sure why you want it.