Hello,

throwaway for obvious reasons. I'm not really sure how to start, so I just try to caputre the most important things to hopefully have some understanding.

My sister and I grew up very, very sheltered. I didn't have my first kiss until I was 18 and my sister until she was 17. Seeing our ages, you might see that there is some correlation. While we obviously weren't totally oblivious to porn(I am proud to announce that I dared to visit the first site with 15... that sheltered), I believe my sister had some more exposure to different kind of material. So two years ago she dropped some hints about kissing and trying, which I always laughed about and she seemed to put is as a joke too. It never even would cross my mind to do that.

Well, one day she entered my room and told me how we needed to talk. Totally serious, I still remember that moment. I joked something about whats the problem and she said how she seriously wants to try kissing... I was taken aback, but she begged me to not look at her like a monster. I don't remember her words, but I she was quite ...convincing?. Something about her friends all having lost their virginity, she not having done a single thing with someone else and not daring to out herself to her friends. I think. Something along those lines. Anways, it was extremely awkward and I declined, because... well, it was awkward and I didn't know to react. She made me promise to not talk to anyone else about it.

After that bomb I couldn't get it out of my head however and whenever I saw her, I thought about the kissing proposition. I was thinking that the idea might not be THAT bad. I only knew two girls who had boyfriends already and... I could TRY something at least. To know how it is, you understand? I don't know, it's hard to explain. But it was an extremely uneasy feeling. Do it? - But thats fucked up, as we are brother and sister. Brother and sister don't do that stuff, right? Don't do it - That's the rational way, but somehow the interest is there.

And how else should it be when reading my title, I approached her and agreed to test it out. This went on for about two months or something because we liked it, until I suddenly got hard during one. I freaked out, my sister freaked out, we both pretty much went out of each others ways. I was stressing myself over getting a hard on and what she might be thinking. Many awkward months followed because we or I couldn't handle the situation.

So, forward until three weeks ago, we were getting along fine again. We haven't talked about, but it was your everyday sister/brother relationship, or at least the way I knew it before the kissing stuff happened. My friend circle is still very small, my sister became a bit more outgoing, but is still the shy, awkward one that spends her free time mostly at home. Anyways, three weeks ago we had a few guests over for dinner who were invited by our parents for my dads birthday. A couple was a bit flirty with each other during dinner and we all had a glass of champagne. When I left with my sister to leave them downstairs, I guess it's because of the couple and champagne, she suddenly mentioned the kissing again. How it wasn't so bad. I kind of went along with it... I mean, it was nice. So we talked a bit and were at it kissing again. I dont know if the champagne affected her much, but I personally didn't feel intoxicated at all. I'm not drinking a lot, but it was just one glass... So this plays into how I feel awkward about allowing it once again.

And to make matters worse, it escalated over these three weeks. She started getting more aggressive, always asking me if shes a monster for this, and I always reassured that its okay, in the heat being a bit more aggressive myself. I mean not just kissing, but grabbing some parts, licking the neck... It was like a contest of dares and who would do more.

And four/five? days ago, she came into my room, we started off, and after intensely looking at me she pulled down my pants and started with oral. I was shocked. Really. I still am. But I reciprocated. And this brings me to the really big problem now.

Looking at this rationally, this is fucked up. This is going beyond trying out. I catch myself thinking about sex constantly when seeing her and I'm near a constant hard on when shes near me. There is so much sexual tension now and its eating me up. And it doesn't seem different for her. But we still continue, because it feels just so good.

And I have no idea if I'm catching other feelings. She is suddenly doing way more with me. I wouldn't call it clingy, but the way we interact non-sexually has definitely changed too. This is all so awkward. Writing this I'm constantly ashamed of myself because everything is totally expectable for some teenagers to try out and I would say why not, but this makes even my stomach squirm. I'm on an emotional rollercoaster and don't know how to handle this. I'm currently also playing with the idea that sex would be fine if she has the pill and I condoms... and its throwing me so off. Because I can't do this. This is a no go. But everything is pointing towards this escalating even more. One half in me is telling me to pull all the brakes, the other is pushing on the gas relentlessly. I am torn and I am afraid. I simply don't know what to do.

What if she is serious and this continuous? What if I'm really starting to develop feelings for her? Or already have them? What if we are each others replacement because we haven't had anyone else? What if she has feelings for me already and I destroy our relationship completely by breaking it off? What if anyone finds out about this stuff? Is this really that bad?

Thanks for any advice, helpful or not! I really need inputs, different that "ugh, gross".

tl;dr: Me + Sister, went from kissing to break to suddenly escalating into oral and I'm emotionally fucked. What to do.