Hes gone up into here ovaries, thats as far as it can probably go without causing some king of rupture. But yeah, hentai lies cause this would probably hurt, not be crazy orgasmic.
Iz no expert on anatomy, but if I remember from the horrors of health class, the ovaries are not attached to the fallopian tubes but rather sit just after there ends. So, if something was long (and flexible) enough, it could go up the fallopian tubes and then out into the abdominal cavity uninhibited. (Don't take my word for it though because I have *no* medial background *whatsoever*.) Also, its an alien: They can do whatever the fuck they want (and fuck whatever they want), and it's all good.
I like this pic just the way it is because I am turned off by blood. And yeah, don't analyze hentai :) *should take my own advice*
Some hentai-artists just tend to do way to detailed bulges from the things that get inserted, as if there just was a thing layer of skin between the vagina and the outside.