This is something I have never spoken to anyone else about, ever.
I am in my mid 40's, married, 3 DCs.
My childhood was pretty troubled...DV, alcoholic parents, emotional abuse etc.
I have an uncle who, as a child, I worshipped. At the time he would have been mid 40s. He was DMs younger brother, lived in a cool city, had lots of money, liked and was friends with cool bands etc. In my teens he would take me to gigs, lend me records etc. I thought he was the coolest thing, as did his other nieces and nephews. We vied for his attention. To a degree he played us off against each other. When I was 16 he got divorced. They had 2 young kids and I would baby sit. One night I was staying over so I could look after his kids (he was coming back late) he got into bed with me, hugged me from behind, then stuck his hand in my pants while he kissed my neck. I didn't say anything or move or fight...I just lay there. After a while he said 'I'm sorry, that's all we can do' then got in his own bed. No mention of it was made in the morning.
At this point in my life, in all honesty, I was fairly off the rails. I drank a lot, took a lot of drugs, and slept around. I validated myself through sex and only felt that I had value as a sex object (obviously I have only realised this since...At the time i thought I was just free spirited).
Any way...I still idolised this man in lots of ways. Next time I babysat he kissed me as I left...properly, full on kissing. I pulled away and he said something along the lines of being unable to help himself and how I was being the mature one. In honesty, I was flattered and felt that I had 'beaten ' the other nieces and nephews in the battle for his attention. 
I was pretty screwed up and clearly desperate for attention.
Anyway, over the next few weeks he continued to comment on my appearance in secret at family gatherings etc...he would come into a room where I was alone and tell me I looked hot and did I know what I was doing to him.
Long story short, one night I went to his house with my mother. We drank a lot...most of a bottle of whiskey. Yes..I was 16, 17 at most...Yes, my mum let this happen. Any way, my mum left and we ended up having sex. It felt consensual. In fact, I initiated a lot of it. I was relatively sexually experienced. 
After that, no mention was ever made of it except that he asked me to never tell anyone. I kept away from him after that, though I didn't at the time equate what happened with abuse, especially as I initiated some of it, including giving him oral sex.
As I have got older I still see this man regularly at family events. We are polite and no mention is made of it...but as the years go by I can't help but go over it in my head. I'm the age he was now, and I sure as hell don't find 16/ 17 year olds sexually attractive. At the time I thought I was an adult, but clearly I wasn't. My kids are older than that and the thought of them having that type of experience with an adult horrifies me.
I also worry that I didn't speak up and he has other nieces. I tried as a teen to believe that I was in some way especially attractive, rather than that he was a paedophile.
I also suspect that my aunt (DMs sister) and my mother had some inkling of what was going on but chose not to address it..They too idolized him to an extent. Also, my family is generally a hot bed of lies and deceit and dodgy behaviour.
I think I'm ok. I'm messed up in some ways by my childhood...EDs, anxiety etc. But I'm happily married, with great, functioning, happy kids.
I sort of feel like either this should have marked me more and the reason it doesn't is because it was my fault, or that I am suppressing how I feel about it and one day it's going to hit me like a ton of bricks.