(as me being a guy) Guys enjoy to put their arm around a girl because, it gives them a sense of superiority over the guy who doesn't have a girl like the one he is holding onto. Another less shallow reason is that, he just wants to be close to the girl, this is a sign of affection, girls will probably never fully understand.
I know that it is kind of gross but a girl puts her hand on the guy's waist or in his back pocket.
She will rub your back and hold your hand that means she wants a kiss and put your arm around her
It doesn't have to mean anything. If the girl wants to walk with the guy then I'd only assume that the two are friends, nothing more unless she's trying to put her arm around him or something.
No, he just like you
They may be lesbian or cousins or friends
Make a move on her. Put your arm around her or something
He will put his arm around your shoulder and get real close.
put your arm that is close to him around him! Leave your other arm hanging, it might seem funny but it looks cute!
put your arm around her and hold her hand if shes scared :)
we put our arm by folding hand
put your arm around the girl or boy and lean in slowly