✔ 最佳答案
If he loves another girl, you must give up. If you go to be the 'third person' , the boy will hate you.
If there isn't anyone he love, you can try to be friend with him. remember, don't let him know you love him first. Just be yourself when you are talking with him. After one to two month, if the boy really doesn't have any girlfriend or someone he love, you can do something as a tip to tell him you love him. (For example, you can celebrate his birthday with him. Or you can give chocolate to him on Valentine's day. Remember to tell him it's not only he can receive your chocolate. You must look at his face's expression. If he looks a little bit sad, that means he maybe start to love you. If not, try to do something like that again) If you are sure he loves you, you can wait for him to tell you his love. If you can't wait, just tell him you love him.
p.s. If the boy doesn't love you after you have done the things I told you, try to forget him and find a person you really love.