Not Sure What To Do About Best Friend

So one of my best friends is a good family friend because she dated and got engaged to my now deceased brother. He died about four years ago. She still comes to family functions and sees my family frequently. She is kind of like a sister to me.

We are currently on a trip in Ireland and something happened that has never happened before. We were pretty drunk one night and we were being kinda touchy and then she ended up sitting on my lap. As we were talking I started subtly messing around with her sexually and she was totally letting me. So I went a bit further and legit stuck my hand down her pants and kept playing around with her and she was getting into it. We stood up and moved over to the bed. Then all of a sudden she started going "No this feels wrong, you're (my brother's name)'s little brother, you call me your sister, what would your family think, how are we supposed to act around them after this... (the list goes on". When she gets up to leave she is like "I'm gonna go to bed. Probably gonna play with myself first though.... Night". Then she goes to her room.

Next day we just go on like normal and it never comes up. It is now 2 days later and it is like it has never happened. Now just me and her are going to Amsterdam in a few days and I am kind of confused. I don't know if she doesn't remember, or if she is just too embarrased to talk about it. But everything is completely normal. She does seem to be looking at me a bit more and kind of hanging out around me more and we are doing more things just me and her. Other than that our banter is the same and nothing else has changed.

I kind of want to wait until we get drunk again in Amsterdam (she mentioned drinking while we were there) to ask her about it. I don't know if I should though. I don't even really know what I want out of it.

I'll admit I haven't had sex in a year so I am kind of going crazy to just get laid, so I don't know if I actually have feelings for her or if I am just horny.

At the same time something happened a few months ago that makes me think I might actually be interested in her. We drank pretty heavily (half a handle of rum) and we ended up lying down on my bed together. Nothing happened. She just fell asleep. I was just lying next to her listening to music and she rolled over, put her head and arm on me and cuddled into me. I know she was just asleep and it was only because she felt comfortable and safe around me. But that was the first time I kind of felt something for her. I felt really comfortable and kind of happy laying there with her. And I wanted to cuddle her but I didn't feel right about it. So I just fell asleep.

Would it wrong for me to have feelings for my dead brother's ex? I know it is kind of odd, but I don't care if he is in some afterlife rolling over in his grave. He spent almost my whole life controlling me. Even though I am finally free of it somehow the shadows of his past still have a lingering affect on my life....

At some level I guess I don't know if I actually have real feelings for her or if I am just thinking with my second head. But if I did would it be wrong?

Is it wrong for me to want to talk to her about it?

What should I even talk about?

I don't even know if she rembers the other night, but I really want something to happen. But I wanted to give her space. The only reason I want us to be drinking when I do is so that I don't feel like it will be so awkward.