Don't watch with gf unless you already know her well. It might freak her out. There are also some disgusting/disturbing scenes that probably mean no sex after watching.
You can watch it alone, though. It's broken down into episodes, so you don't have to commit to full 90 minutes or whatever. You can watch 5 minutes of the first story and then pause. There is no connection. It's basically 12 short stories or something.