Just talk to the guy and become friends with him first. Maybe flirt a little bit, but don't be shy! Guys love confidence and girls who are comfortable with their personalities :) Good luck!
I would confront the girl or warn your boyfriend
Boyfriend.
Mostly a girl gets a boyfriend at the age 13 or 15
Ask the girl.
If a girl keep on talking about her ex-boyfriend to you that means she still loves him!
If he wants to marry another girl he's not your boyfriend.
Then she has to choose you or her boyfriend.
If she has a boyfriend, leave her alone.
That she isn't ready to have a boyfriend yet or she is to busy for a boyfriend.
Get a boyfriend and love him..
You don't.
if i where you i would tell the girl that likes that boy that he has a girlfriend.that is what i would do.