Was this even rape?

I was telling this story to my partner the other day. I always thought he took advantage of me, but my partner said it was clearly rape. I'm not sure what to think, I was hoping to get outside opinions.

When I was 18(F) and had just moved to university. My roommate was away, so one of my 'hometown' friends suggested that he come over to visit for a day and stay over. Awesome.

The visit was great, we were chilling out and catching up. We went to get food and he bought a bottle of whiskey for the night (we're in the UK).

Night fell and we started playing cards. It was just us two alone. The bottle of whiskey was next to him, and he was pouring the drinks. We had to drink every time we lost a game, and I was terrible so I was knocking quite a few back.

Important for context - I am autistic, and at the time I was very naive for my age (I probably still am).

He suggested we do a game of strip poker. I thought it would be funny - I had never seen him in a remotely sexual light before and thought we were just bantering. I was quickly down to my underwear (I refused to take any more off, since we were just mates). He was pouring drinks the whole time, I was completely wasted - I have no idea how many drinks he had had.

During this time, he propositioned me multiple times. I wasn't interested, and he was in a relationship, so I turned him down. I didn't take it very seriously, since it didn't make sense to me that he would want to have sex with me - we were just mates! However, we reached a situation where suddenly I was wasted, in my underwear, alone with this man. He propositioned me again and I gave in. I don't remember much of the act itself, just that it happened. He left the next morning and I didn't see him again for about 2 years. It also came to light that he was going around and having sex with all the women in the hometown friendship network, so he clearly came to visit me for an exact purpose.

My personal narrative of the situation (its been 13 years) was that he wanted to have sex with me, he provided quite a lot of alcohol, and then I eventually gave in to him. I always said that he took advantage, that I was naive to fall for it, but that I wasn't an innocent party (since he was cheating on his fiance with me).

However I went though this story for the first time with my partner, and she said (kindly) that I was in denial and that it was rape. I have been raped in my life, but these happened after the events if this post.

I don't know what to think anymore. I was hoping to get some outside opinions on the situation. Was it rape? Or was I just naive and let him take advantage?