✔ 最佳答案
very simple, tell him like this ...
"XXXX, I know you love YYYY, for years, but YYYY have not give you any response, I feel so painful for you, because I love you, I want you to be happy, when everyday, I see you in pain and poorly loving her, while she is not responding to you, I feel more sad, because I am quietly in love with you for 3 years... " and see how he response ?
Don't over expect anything after saying this, if the boy is reasonable, he will know you at least care about him and love him ... he may consider you as a girlfriend slowly, if you are at least not that "bad" compare with the other girl ...
boy shift target very fast, so you have a big chance if you are confident.
hope all help
good luck