Should've?

Isn't "should've" correct? Not according to my spell-checker! What say you my supermegadioites?

We shall determine our own rules of English!

Your Grammar Knits Socks In Hell!

It has been implied that our grammar on Supermegadio!!!!! sucks. In particular, in our placement of apostrophe's. It should be known that, as supporters of the one true rock god, we feel it is our place to break laws as we feel fit. Especially you're antiquated grammar rules!