Something strange happened on the bus

This is a bit of a long story.
I think they call them intercity buses? Anyway, I was on my way back to Seoul from a new city in the metropolitan area, riding an intercity bus with a layout where two people sit side-by-side.
It was a little past rush hour (around 7:30 PM to 8:00 PM), and there were only about five or six people on the bus, including myself. In fact, most of those people had boarded at the same stop I did.
Since there were plenty of empty seats, as soon as I got on, I went to a section in the middle of the bus where two seats were vacant and sat by the window.
Since it takes about an hour to get to Seoul, I was planning to close my eyes and get some sleep, but then a woman boarded at the very last stop, the same one I had boarded at.
To be honest, I couldn't help but look because she was quite pretty.
Was she in her early 20s? (At most, maybe mid-20s?)
She had an impression similar to Choi Yoo-jung from I.O.I. She seemed a bit short (maybe slightly under 160cm), but she had very fair skin and a somewhat sultry vibe. Regarding her outfit, she wore a shirt as an outer layer, but underneath the unbuttoned shirt, she wore a low-cut camisole—she had a very sexy style.
However, after looking around for a seat, this woman came over and sat right next to me.
With the bus so empty and most seats being vacant, I thought to myself, "Why did she choose to sit next to me of all places?" But at first, I honestly thought, "It's probably just a coincidence," or "Maybe she thought I looked somewhat polite because I'm wearing a suit and there might be more people boarding at future stops." I didn't think much of it.
You know how it is.
When there are many empty seats, if you sit by the window, a perverted man might sit next to you at the next stop, so a person who looks decent in a suit might preempt the aisle seat next to the window seat. Anyway, I was thinking as rationally as possible.
Because I didn't think anything was going to happen to me.
But as soon as the bus started moving—actually, almost immediately after it started—this woman began to doze off. Her head gradually started leaning toward me... At first, I just thought it was a funny situation. "She must be really tired."
I wondered, "Is she drunk?" but there was no smell of alcohol, so she didn't seem intoxicated. I just assumed she was exhausted and tried to wake her up by lightly nudging her shoulder.
As expected, when I nudged her shoulder at first, she woke up immediately and pretended to look straight ahead. Fearing she might feel embarrassed, I intentionally looked away out the window to avoid making it awkward. But after a moment, she started nodding off again.
I kept nudging her shoulder, but this time, she wouldn't wake up even when I nudged her. The bus continued to the next stop, and then the next, but only one or two people boarded, and the bus remained sparse.
At some point, her face was leaning completely against my shoulder, and the new passengers boarding the bus probably mistook us for a couple.
At that moment, I was really conflicted. "What on earth is this situation?" "Is it right to wake her up?" After much deliberation, I gathered my courage and lightly tapped her shoulder with my fingertips.
Then she opened her eyes and straightened her posture, but her expression was strange. She just stared straight ahead with a somewhat tired expression, as if nothing had happened, as if it were perfectly normal...
I thought she might say something like, "Oh, I'm sorry. Excuse me. I must have been tired," but I couldn't think of the right words to say to her, who was just staring forward without saying a word.
Looking back, I think my expression must have been incredibly awkward. To avoid making her feel embarrassed, I tried to give a comfortable smile and said, "You must have been very tired," but whether she heard me or not, she just kept looking forward and didn't even glance my way.
I just assumed she was very embarrassed and let it go.
For a little while, she seemed to have regained her senses; she started looking at her phone and doing something. I thought it was just a brief incident and was deciding whether to lean back and sleep, when the bus entered the highway section.
About 30 minutes until the next stop? The bus was still almost empty, and I planned to get off at the very next stop after entering Seoul.
However, once the bus hit the highway, she started dozing off again. I tried to wake her by nudging her shoulder, but she ended up burying her face directly into my shoulder.
I gathered my courage again to tap her shoulder with my fingertips, but she opened her eyes, stared intently into my eyes for a moment, and then leaned her face back onto my shoulder and closed her eyes again.
"What is actually happening?" I was having a bit of a mental breakdown. To be honest, saying it was just a 'mental breakdown' would be a lie; I could only think, "Is she giving me a sign?" or "Is she seducing me?"
Furthermore, ever since she first started leaning on my shoulder, I could see her exposed cleavage in my line of sight, but now that she had buried her face, more than half of her chest was completely visible.
Once we were on the highway, all sorts of thoughts raced through my mind. "Is she a 'honey trap' (gold digger) like I've heard of?" "Why is she doing this to me?" "Is this a one-night stand?"
Ridiculously, I couldn't even wake her up; I just sat there in silence, lost in thought. My thought at the time was, "Let's just let her rest for now and think about it."
After riding for about 20 minutes like that, she eventually placed her hand on my thigh. It wasn't near my groin, but she placed it firmly right in the middle between my knee and my groin. I thought, "Since we're about to arrive in Seoul, this must be her final sign."
Since I have someone I am planning to marry, I was actually very conflicted. Honestly, rather than thinking, "I can't because I have a girlfriend," I think I was thinking more, "This is such a sudden situation, can I get away with this without getting caught?"
As we entered Seoul and the next stop approached, I lightly leaned my head against hers. Her head was buried in my shoulder, and I leaned my head on top of hers. Her hand remained on my thigh until the very end...
Finally, the bus arrived at the next stop. Someone had already pressed the bell, and as soon as the bus stopped, she suddenly jumped up.
She then strode off the bus, and since it was my stop, I followed her off.
It was a central lane bus stop, and she stood in front of the crosswalk on the exact opposite side from where I was. To go home, I had to cross to that opposite crosswalk.
The light for the crosswalk on her side turned green first, so I gathered my courage, approached her, and spoke.
"Excuse me."
But she suddenly widened her eyes with an expression that said, 'Why is this stranger talking to me?' and looked at me, saying, "Yes?"
I left her with a comment that I still wonder why I even said—"Ah, no. You must have been very tired"—and just turned around and crossed the crosswalk to go my way.
Even as I walked toward my house, I felt a lingering curiosity, so I looked back at her. She crossed her crosswalk, wandered around for a moment like someone who didn't know where to go, and then eventually headed toward the subway station.
What kind of person was she? Was she really seducing me? Or was she just so exhausted that she was out of it, and I was just overthinking everything? It happened a while ago, but thinking about it now, it's quite dizzying.