Rat Bastard in What Happens Next?

I opened up my heart,
I opened up my home.
But then I made the mistake,
of leaving you there alone.
I wanted to give,
you decided to take.
Thought our friendship was true,
but you proved it was fake.
Rat Bastard! Rat Bastard!
You acted quick,
but I acted faster!
Now time has passed,
I can forgive not forget.
Can't say that I hate you,
but you'll never again be a guest.