OK. This happened on 31st dec, been thinking about posting since then to get opinions, seeing as I can't seem to break out of the numb feeling to form one of my own. I am 25, have 2 DD's under 5 with my partner,been together about 7 years now. I am 29 weeks pregnant with our third child. We live together.
Looking through the files hes recently downloaded, whilst he was walking around in the background feeding kids etc,so I wasnt being sneaky, I noticed some general porn saved (an orgy one and a nurse-themed one) He knows it pisses me off, so I deleted them and had a bit of a whinge (not a HUGE deal to me, as our sex life is pretty non-existent due to my anaemia/seem to bleed easily after sex/hip pain)
so a 'normal' wank to a bit of vanilla porn is the best of a shitty deal to me, I feel I cant stop him using it.
Carried on randomly looking, and saw two quite different films saved that hes downloaded- one was titled something like hot german Teenager fisting, and the other was called Real Drugged Rape.
I clicked on it to see what the actual fuck it was, and as the title suggests, it appeared to me to be a young (18 to 20 at a guess) Asian woman in the back of a car, VERY drowsy/almost unconscious, being fondled/exposed/touched by some older man, filming on what appeared to be shaky handheld camera.
I skipped through it, saw a few seconds of the woman face down being raped etcetera. All of which is BURNED into my fucking memory. It pops into my head constantly, it is making me ill with stress.I felt like i was genuinley going to faint, due to shock i think, and utter, utter disgust. And I asked my partner to come and explain it. He said he "downloaded it out of curiosity" and when asked if he finds it in ANY WAY WHATSOEVER a turn-on, he vehemently denied that it is, likening it to watching executions etc that are real and available online (I didn't know he would watch that either!!) I didnt really look at the fisting one, but its the same category, relatively young woman being used and violated.
I said to him that even if the rape one isn't a film of a 'real' rape, the fantasy of raping a very young woman WHO IS FUCKING DRUGGED (or acting?! how the fuck can you know for sure) is completely wrong to me, as a mother if two DDs I cannot tolerate a person who would even look at it just out of curiosity, much less select it, download it, and then keep it. He apologised and said he is stupid, didnt 'think'.
Despite the fact he says he gets nothing sexual out of it, I am obviously not believing that. Why the fuck else would he download it? (thats a genuine question, I cant think of any other reason why, and the resulting congnitive dissonance is making me ill. I dont want to believe it is true, because it will make the imminent birth of my child etc very hard if Im alone.)
So, from a feminist point of view (am trying to use that as an approach to my life, have very low self esteem too) I am thinking I should remove him from mine and my DDs presence, I feel THAT strongly about it. He is otherwise a lovely-seeming person, a bit cold and robotic sometimes but funny, warm, and has what I would previously have described as vanilla tastes re porn, sex etc. He says fisting is normal? I didnt think so, but dont really know in terms of general acceptability.
He certainly hasnt tried to hide it as such,knowing I have free access to his PC, just dont use it. He didnt expect me to fidn it though.Also found that in the fortnight before Xmas he has joined a dating site and a 'sex in the UK' site. When I confronted him, he says it was curiosity again 
and he would never actually cheat, just clicked links and had a nosy.........
I feel like a total twat, due to give birth soon, and obviously at some point he is probably going to fuck me over. Current emotional situation is totally numb. I havent done anything or said anything conclusive to him about the whole thing because in the past I slept with someone else once, and so am battling with remaining objective. Because till now he hasnt put a foot wrong that I know of. I cannot believe how vulnerable he has made me feel.
Sorry for length of post but trying not to drip feed.