Is she his step sister?

Run. Away. Fast. Now.

GROSS. Personally, SO not normal...unless, like Adam said...they're step-siblings....then again, EW.

Total psychopath, no. Someone with some potential problems, likely.

Sisters are still girls. Just cause you're related doesn't mean they stop having boobs.

I'm pretty amazed that he's been willing to admit this to you. If your relationship isn't very serious yet (at least from his perspective) I'd lean towards crazy side. If it is serious, take it as he's gotten VERY comfortable with you to admit something that could cause him a lot of embarrassment. I'd probably ask him why he admitted to that.

Is he trying to see how freaky you are? (I'll tell you my weird thing, you tell me yours.)

Is he trying to be honest with you about his sexuality so that you don't get a big freakshow surprise after 10 years of marriage and 3 kids later?

Is he maybe confessing out of guilt? Has he told you about other sexual fantasy about other girls before?

That is not normal. It doesn't make him a psychopath, but you need to be really careful.

I too had an ex long ago who confessed the same thing. I even went as far as to ask him if anything (abuses, etc.) had happened. Luckily, we're still friends and nothing had ever culminated beyond fantasy--so far as I know. So, I go with the above post and agree its more of a proximity infatuation so long as he knows where those boundaries are. Also, you have to watch very carefully and discreetly how they interact, particularly, his sister. Are they uncomfortable around each other? Is she uncomfortable around him? If so, then it might be a strong indication that it is time to jump. Listen for the red flags and go with your gut on this one. Don't make excuses/justify. If it makes you too uncomfortable then leave.

I would encourage him to seek some kind of counseling on this.

That is disgusting. Please be rid yourself this monster

I just hope he's not testing her reaction my calling them 'fantasies' when they really happened. My sisters ex-husband did something similar - turns out he did molest his sister for years.

Only scenario where he might get a second chance is if a) nothing ever happened and b) he was high or something at the time and maybe something slipped out that he never would have shared sober.

If he was sober when he told you, run.

Wait. By sexual fantasies does he mean hot DREAMS? Because then it's kind of different. There's some weird psychological reasoning to that issue.

But if he's just sitting around thinking about what gets him all hot and sweaty, and it happens to be his sister...then...good luck.

Wait. If by sexual fantasies, you actually mean he had hot DREAMS, then there MIGHT be some weird psychological reasoning to that.

But if he was just sitting around thinking about things that get him all hot and sweaty and one of those things happened to be his sister...then...good luck.

No question...RUN...HIDE....CHANGE OF ADDRESS! Weird, gross, psycho...pervert.

How old was he when he had these "fantasies"? If he was really young it could have just been a boy going through puberty.

wow... psycho... ditch 'em.

If it is your first date with him, then maybe he's trying to make you think he is crazy so you'll never want to date him again, but if your in a relationship with him well...... Let's just say good luck!

Wow.. thats some 'holy shit' level of emotional disclosure, but definitely not normal. Not it a 'hey, you're someone I want to mix DNA with' way, at any rate. I'd say go with your feelings on this one, as long as your feelings are along the lines of 'I'll see you some other time thats.. different. .. to this time... bye!'

I'm really hoping this is not some hillbilly thing here...Springer is twisted enough already!

I agree with finding out more information, watching discreetly, etc. Im not saying run by any means, encourage counseling...... but here is my only true worry. If he fantasizes about his sister (not dreams, fantiasizes!) at his age (or as an adult), then that seems like it would increase the chance of him also having similar thoughts about any future daughter he might have..... and thats extremely scary! So I really think you should encourage him to talk to someone! Even if you guys do or dont stay together, it would still be a good idea for a professional to step in.

There's a pink elephant in that room! You better leave. Or wait for it to trample you.

Hmm...there could be a lot of circumstancial evidence to go along with this one, so until the poster of this thread elaborates, I don't think we should make any serious judgement calls. All I can say is, this is a serious warning sign.

Well, let's see. Are you dating Luke Skywalker? If so, then it's probably okay (Leia did look pretty hot in that slave girl outfit, after all).

Funny how, if a guy says he had fantasies about his teachers when he was a kid (underage), or even that he has rape fantasies, most people are willing to excuse that and say, "well, a fantasy's just a fantasy, so you shouldn't judge." But as soon as you bring up incest, everyone gets weirded out.

That's not to say that you shouldn't be weirded out, oh no. Sometimes fantasies can point to disturbing personal issues indeed. But sometimes they're just fantasies. People can fantasize about things that would be completely distasteful to them in real life. You're not the thought police, and it's not your place to tell him that his fantasies are wrong.

But Liz Tee makes an excellent point. Revealing his "fantasies" may just be a gateway into something much more sinister. I think you've really only scratched the surface here, and you might not want to find out what lies beneath.

Unless it's a step sister he didn't grow up with, run away now.

Everyone here is saying "oh thats disgusting!" or "Oh, he's a total psychopath," but it is human psychology. there have been several statistics showing that almost everyone in the world has faticized or at least dreamed about sex with a family member, most being either mom or sister. As odd as this seems, its completely natural. What I want to know is who the question writer dreampt about :P