The first lines are:
Nice guys finish last,
that's why I'll treat you like trash.
It's not what I really want to do,
but you only date bad guys,
so I'll give it my best try
to treat you the way you want me to.
It's funny because there's a grain of truth to it. I mean, there must be or we wouldn't love those fictional bad boys so much. (Warning for my sensitive readers. The song contains the h word.)