Source?

mahou_shoujo_ai

As with Himekishi Lilia, avoid at all costs if tentacle rape, impregnation, torture, and/or guro aren't your cup of tea.

You get used to it.

I wanna be "raped" like that. O_O kinda...

there are many vids of this movie on a web sight called www.tifahentai.net

Oh good lawd

Good God!
...can't unsee ಥ_ಥ

Which episode is it?

Lol, it has the french kiss tag. (Also, I found out it's episode 4; It's a rather short scene because the tongue-fucking gets interrupted. Kinda dissappointed now.)