Lucky Boys Confusion

I'm gonna steal your girlfriend
I went to my boys house I met his sister
I knew right then I had to get with her
She had a boyfriend he wasn't worthy
His friends all say he's a wannabe junkie
I know that this might be wrong but
I'm gonna steal your girlfriend
I know I will steal your girlfriend
I don't really know her; her boyfriend's richer
But I find her smile so irresistible