This option should exist

this mode has a few flaws, mainly, that you cannot re-open pages you have closed, even in the same session.

You could also delete certain pages from your browser history as well. It takes a while but it may be worth it.

Because its a nice little function.

Yeah, but it sounds more like something that should be developed as an add-on by a third party, or something.

Yeah there's a Google chrome extension. It's called Gehta-wyfe. It eliminates the need for porn