I'm Open

I'm open, you can enter me
You can exit me, you never have to ask
I'm open, open my head
Cut open my head, take the lid off my head
Empty out my head
Plunge your hands into my open head
Take huge handfuls of head stuff
Make mudpies, make a sculpture
Make a collage of blood and brains
Make sweetbread and invite me to dinner
Enter me and exit me
I'm open
I'm open
(Repeat)
You never have to ask