You respect their relationship. If you were in the girlfriend's place, how would you want another girl to behave?
Leave him alone. He's already with someone else. Find someone who's single and date them. There's plenty of them out there.
No he should only concentrate on his studies. It wrong to have a girlfriend in small group of age.
If you are in middle school and a boy flirts with you, but has a girlfriend, you should ignore his flirting. Even if he likes you, he still has a girlfriend. You should respect his relationship with the other girl since you would not want him to flirt with another girl if he was your boyfriend.
You should fancy him from far away. If he knows you fancy him, try to move on but if he doesn't, don't let him know.
You schoul let him know ASAP otherwise he will be in the dark. i know. i am a boy. teen, actually.
act normal
If a boy has a girlfriend then he is considered taking and you should leave him alone and later he may break up with his girlfriend.
Yes, it is absolutely okay to not have a girlfriend while in high school. Relationships are not a requirement and everyone progresses at their own pace. Focus on personal growth, relationships will come in due time.
You should do nothing. He is not good for you.
You can not get a boy to fancy you. If he doesn't like you, nothing you do can change that.
If you like him then go for it!
First check if he has a girlfriend then if not get your friend to ask him if he would kiss you then check if he had a dirty girlfriend before then you can go with him after school and kiss him. hope that helped ;P