My sister initiated out of the blue

Sup folks, teenage guy here! Just wanted to share Friday evening's event which took me by surprise! Apologies in advance for any language errors as English is my 2nd language (I live in northern Europe).

For context, I live with my parents until I start college, but spend most weekends with my sister (whom I'll call V), mainly because my parents, in short, are practically strangers to me. V got her own place half a decade ago and is now in her mid-twenties with a great life ahead (having recently attained a medical degree).

So on Friday I went from school to Krav Maga class, then the 2-hour train ride to V's place as usual, where I had a long shower before crashing on the guestroom bed in my underwear (too exhausted to bother changing clothes), drifting into slumber almost instantly.

At some point I quietly woke up to V on top of me naked, rubbing her body against mine, which for a few seconds I assumed to be a dream. I tried to ask what she was doing, but she gently hushed me and told me to relax, then kissed me whilst caressing my cheek. She went on to kiss, lick and suck my neck, then my chest.

At one point I got ticklish and told V, causing her to giggle and start tickling me deliberately, which turned into some brief hug-wrestling with mutual laughter. Before long she was on top of me once more with my arms pinned down, nibbling my nose and asking mock-sternly if I give up or if she has to punish me. Knowing she'd rather die than actually hurt me, I just asked curiously what "punishing me" meant, to which she replied she'd ride my face. I said I was legit fine with that if she liked; she lit up and didn't hesitate, giving me a peck on the lips before I found myself eating her out, my arms remaining pinned down.

After a few minutes of this, V switched to a 69, going down on me as I continued eating her out; we must have kept doing this for nearly 10 minutes. It was audibly obvious she loved it, so much that she eventually came all over my face (this baffled me as I had never eaten out a girl/woman and had assumed female ejaculation by oral stimulation requires very good technique), then slurped up the pre-cum that had leaked out of me.

V started licking and sucking her fluids off my face and simultaneously started riding me. In doing so, she would alternate between rubbing her breasts in my face (with me sucking on them), gently choking my neck, deep-kissing me whilst caressing my face, and licking/sucking her fluids off my face. She eventually had a second orgasm, then went down on me for a few more minutes before I came in her mouth, all of which she eagerly swallowed.

After that, V snuggled me up to her and we cuddled stroking each other's backs. Fascinated, I remarked that she's quite feisty in bed and clearly knows how to take control. With a half-serious expression, she admitted she can be far "worse" than this, having been an unapologetically sexually dominant woman for quite a few years, with significant experience with both guys and girls at various times in university. I asked (for her sake) if the men had worn condoms since she obviously couldn't know who else they had slept with. With an appreciative smile she kissed me saying she loved me so much for caring to ask that despite being the younger one of us, and assured me she always insisted on condoms - myself evidently being an exception - even though she's always been on COCP as well (after all, it doesn't protect against STDs). I also randomly commented that I found her moans silly cute; she told me to shut up and stuck out her tongue, to which I replied I really think they are and wasn't saying it to tease her. She said she was just joking and gave my moist cheek a lick and light nibble, then kissed me a bit more and said she loved me (to which I said she's beautiful) before we went to rest, V presumably leaving the guestroom once I had fallen asleep.

As I said at the start of this post, it still feels a bit surreal that this whole thing came about. Not sure if my poor social/emotional intelligence (no doubt stemming from autism) has its part to play, but I didn't see it coming in any way whatsoever, nor have I ever thought of V in that manner.

So did I enjoy it? Absolutely, I found the physical intimacy very cosy and I got what I interpret as a great oxytocin kick from it (plus, I am not ashamed to admit I have a weak spot for the gentle domination V exhibited).

Am I now craving to do this with her going forward? Not really tbh, though I am more than happy to if and when she feels like it (barring any relevant change of circumstances obviously). As far as I'm concerned, it merely constitutes a potential added element to our relationship; it hasn't fundamentally affected things between us, nor do I wish for it to.

I haven't yet got to asking V how come she wanted this with me and why now all of a sudden, because I'm struggling with how to word it the best way so as not to make it a huge deal. Although I happened to be perfectly cool with it, objectively speaking it was pretty risky behaviour to come on to me like that, which is out of character for her and makes me somewhat concerned for her. Incest, after all, clearly isn't for most people, often considered an unforgivable line to cross, so purely statistically speaking my reaction to her initiative could've been radically different. Thus, I'd ideally like to casually broach the topic in the near future for her sake, as a simple matter of open and honest communication if nothing else, something we have always strongly cherished between us.

Just wanted to get this off of my chest. Should you have any thoughts or questions on this, I'm all ears. Thanks for reading!