Do I tell my boyfriend about the sexual assult / rape that I experienced almost four years ago?

This is my first time recounting this in a very long time, so please bare with me.

A few months before I was about to leave for university (age 18 going on 19), I was at one of our regular parties. I was happy because all of my friends who had been at university were back, and I was getting pretty drunk. I got to the point where I was throwing up everywhere and passed out on a couch. This was partially due to a drinking game, where I later found out people were tricking me into drinking more, and because I was already fairly gone, I didn't realise this (great friends). Basically after passing out on the couch everyone went to sleep in various places themselves. I then woke up to one of the people who I thought was my friend, in fact even a close friend, on top of me, touching me, with my shorts and pants halfway down. At this point I froze, not knowing what to do and pretended to stay asleep. During this I remember this person putting himself inside me, and then putting himself in my mouth. This was the point where I regained some senses 'woke up', went to the toilet, and locked myself in and passed out again till morning. I woke up to someone knocking on the door (not the perpetrator) and realised what had happened, and felt really embarrassed as everyone was going to think I had passed out in the toilet. I got up and hid in a corner of the room that the perpetrator and several others was in and pretended to fall asleep again, until he had left. I then 'woke up' up and asked the friend I had come with to go home.

The perpetrator had been a person from my friendship group who I spoke to a lot online. I always found him very strange, and he was far from attractive, but I spoke to him because I never wanted to be a 'bitch'. It was clear he liked me, and had told me several times, but I always made it clear I didn't like him, and actually asked him to help me in trying to get with the guy I actually liked (another person from our friendship group). But I always spoke to him, because despite how weird and creepy some people can be, they can also be good friends. So safe to say I felt extremely betrayed and vulnerable after the events.

I spoke to some friends and tried to receive some support. One managed to convince me to talk to my mum who's response was 'I knew there was something wrong after that party' because I had had a shower and a bath later that day. I also went to the nurse and took my first morning after pill.

I decided not to go to the police because I lived in a small village where despite how anonymous you could try to do something, word would always get out, and I just couldn't deal with people telling me I was a liar, because I was drunk and he was unattractive. I also couldn't deal with the stigma of a 'rape victim' so win lose it always seemed like a lose to me.

Because of this decision not to go to the police, I asked the friends I had told to act as though nothing had happened. But I didn't realise this meant loosing a lot of them as friends.

The male best friend of mine, whom I had told, continued to be friends with my perpetrator, which has lead me to believe, he in fact didn't actually believe me. There was one party with our friendship group where originally I had decided I wasn't going, but then ended up being available, so I asked my friend to check and see if my perpetrator was going, and to ask him not to come if he was planning on it (which I thought was perfectly reasonable considering what he had done to me). So anyway my friend assured me that the perpetrator wasn't going, so I thought great, i get to enjoy this party.

I turned up was having fun, couple of drinks. Then HE turns up. I instantly look at my friend who said he wasn't going to be there, but he just ignores me. I then walk swiftly away from the room he was in, go to the bathroom, call my mum in tears and ask her what to do. She then sends her boyfriend to come pick me up (meaning she had to tell him), and I don't think I've ever forgiven my friend for that. He knew my perpetrator was there, and never once did anything to comfort me.

Anyway, over time my mum told my dad, who was good about it, despite him having the same social awkwardness to awkward situations as me, and didn't really treat me much different afterwards. My sister was also told by my mother, as more of a 'be careful, even your friends can hurt you' sort of thing (which I was fine with) but me and my sister have never actually spoken about it, and she has never treated me differently.

At university, I did have the odd hard time. I tried to tell one of my new friends about it, but she never quite responded in the way I expected, or even wanted, so I spoke to one of my forensic lecturers. She then referred me to a councillor, with whom we came to the conclusion that I was okay and could cope well, so long as I wasn't in the place I grew up. So I never told anyone else about it.

But now I am in a long term relationship, he has told me things about him and his family, and I liked that he confided in me. But I'm just not sure whether or not to tell him, as it doesn't affect me as much as it used to, and he also has always found 'rape' a strange concept, in that he doesn't personally understand how someone could do it, and sort of finds it funny. Not that he'd necessarily find it funny to someone who was raped, but more that he finds it strange that someone could actually 'physically' force someone to have sex. He uses rape as a joke occasionally as well, which doesn't bother me as he doesn't use it in a sadistic bad way, but literally as a joke. So I worry telling him might ruin some of the humour between us.

Im very mixed on whether to tell him, because I want to share and be closer, but at the same time I just don't. But then I worry what would happen if we bumped into the person when we're both back visiting my parents and I freaked out, so I'd have to tell him.

Any advice on what I should do?

I apologise about any English mistakes, or lack of flow.