Sofa King, What?

This is something that's been sitting in my drafts for ages (i.e. years) that I've never managed to finish and post, but I was reading a post on Reddit earlier where a girl was asking how to spot indicators of interest from a guy she was interested in.

Most replies advised her to just make the approach herself rather than try to second guess vague non-verbal cues.

It reminded me of an evening that I think led to FBS becoming interested in me, and I was the one who started it, and it was due to misread or wrong cues.

We were at D's, drinking and listening to music. At the end of the evening, D went to bed. It was late and I was drunk and lazy, so I said that I'd take the sofa. Surprisingly, FBS also said that she'd take the sofa. Now, that was interesting in itself. FBS lived less than 5 minute's walk from D's house. As the crow flies, it was less than 500 metres. I couldn't see why she'd want to share the sofa (I'd already called dibs on it) when her own bed was so close.

My place was around two miles away. A 30-minute walk or a taxi. So laziness won for me.

D had gone to bed, leaving us a blanket. FBS and I were lying on the sofa and I was wondering why FBS wanted to share the sofa with me. We weren't massively close. We were co-workers in the same department, but she was very much D's close friend. And as I have already mentioned, her own bed was 500m away.

So, putting two and two together, I decided it was because she wanted to make out with me.  We were lying, face-to-face. I went in for the kiss. FBS reciprocated for a few seconds before she realised what was going on. She broke the kiss.

"Errr... what are you doing?" she queried.

"Kissing?"

"I didn't even know you liked me."

"I thought you liked me?" I retorted.

I didn't ask why she wanted to share the sofa. I was in my early 20s. I'd made out with a few people before for no real reason other than we could. I assumed this was the case. And I was drunk. Plus, as I have said before, I don't push the issue if there's uncertainty or resistance.

I can't remember how the conversation ended, but I do remember waking up the next day, spooning FBS. I had my back to the back of the sofa with my arm draped across her tummy. That must have happened during the night as I was keeping my arms and hands to myself prior to falling asleep. I was undoubtedly sporting morning wood. 

Even though we had a blanket over us, when D came into the room, I think he spotted instantly the nature of our spooning. We both denied anything had happened. As far as I know, FBS never confessed to anything to D until things did actually get properly physical between us a few months later, but I've always wondered if this was the event that started FBS thinking about us as more than friends/acquaintances?