You do not take up a relationship with him while he has a girlfriend. This choice might be okay for a school event, but it would be on a "professional" level, not a relationship level and you should neither ask nor expect more than that.
yes but don't tell your boyfriend/girlfriend why you are dumping them
You should just ignore them and date someone else better then her or him.
It could be. A mutual friend is someone you and another person both know. If you and a friend both know your boyfriend/girlfriend, then your boyfriend/girlfriend would be the mutual friend.
what you can do is become friends with the person and when they break up with their boyfriend/girlfriend you can comfort them and then express your feelings
Someone has to ask the other to be their boyfriend or girlfriend in which then you will be a couple.
say be my boy friend
Like dating someone. Like someone's your girlfriend/boyfriend then your going with them
It depends on whether you have a boyfriend/girlfriend or not. If you have a boyfriend/girlfriend and you know you can't love anyone more, then no, you aren't crushing on someone you think is cute. If you have a boyfriend/girlfriend but you want this cute guy/girl more, then yes, you are crushing on them. You can't hide your crush from your girlfriend/boyfriend so you have to slowly break-up with them, by slowly starting to hang out with this cute person. If you don't have a boyfriend/girlfriend then yes, you are crushing on them. But don't ask them out or anything if you are crushing on someone else too.
"hang a name" = labeling someone your boyfriend/girlfriend
Like dating someone. Like someone's your girlfriend/boyfriend then your going with them
Look for someone else who has his feet on the ground I'm sure you want someone who only wants you for a girlfriend
You do absolutely nothing about your ex boyfriend considering he has a new girlfriend. If he loved you he would break up with his girlfriend and since he has not then he wants to be with her and you need to accept that. Just because you have broken up with your boyfriend it doesn't mean you can just step back into your ex boyfriend's life.