Rectal...never done it but its dangerous. The movies that you've watched don't show you all the girls who have prolapsed. Yeah, that's when your entire rectum comes out of your ass and usually starts bleeding.
If you live in a major city, the hospital ER guys will laugh behind your back (since they've seen plenty of dumb sex accidents) but they'll patch you up. Of course, you might also be anally incontinent for the rest of your life.
All that being said, by all means take a huge risk of infection and everything else mentioned above.....or not.