Flirty relationship with my (29F) former supervisor (37NB)?

TLDR: My internship supervisor has been giving me a lot of attention, but has never done anything inappropriate. They’re in a relationship. I’m debating whether to apply for a full-time job at their employer.

I’m (29F) a student in a grad program. Soon, it’s going to be the time when I apply for post-grad jobs. I did an internship that I loved, and I’d want to apply for a job there.

AJ (37NB) was my supervisor for that internship. A couple of weeks into the internship, things felt flirty between us. I didn’t think much of it at first. AJ’s in a committed relationship so it wasn’t going anywhere.

Instead, AJ kept making efforts to get closer with me, spend more time with me at work, and see me outside of work (in a group setting). Sometimes, they gave me way too much attention in front of our coworkers, which was embarrassing.

I want to be clear, I really liked AJ. But I didn’t want messiness at work. I went back and forth on whether I thought this was inappropriate, and what I should do about it.

After my internship ended, AJ and I kept in touch a little, mostly about work-related stuff. AJ was basically offering to be a mentor to me.

I started a new internship. AJ was on sabbatical, so they started volunteering there once a week. At first, I thought this made sense – AJ had connections to this organization, and they often do volunteering.

But, things quickly got weird. Every AJ was volunteering, they’d come by my desk and chat, which wasn’t where they were supposed to be. They’d come and see me multiple times per shift. They’d mention that they were planning to come see me, ahead of time. I could feel their eyes on me around the office. My supervisor didn’t like it, and basically shooed AJ away from me.

I started to feel that AJ really wanted to see me. Then why not just ask me to hang out? Because they’re in a relationship? But if that’s not OK, why’s it OK to hang around at my internship?

So then AJ started asking me to hang out. I said yes – I was glad that they were being direct. During, I felt a bit tense, I didn’t feel comfortable opening up. They downplayed their relationship with their partner, which I didn’t like. They told me that they felt like they’d been “too uptight” because they “hold themself to a higher standard than they would hold others” and “question whether they have the right motivations for the things they do.”

My internship and AJ’s volunteer gig ended. A couple of months passed and we didn’t talk. They said I should come visit them at work, but I didn’t go. I started planning for job applications. I’m having a lot of hesitation about applying at AJ’s employer. But it’s a good job, and I found out some other job opportunities aren’t going to happen. So I hit up AJ to get one last check on the situation.

Me and AJ met up for coffee. AJ was super happy to see me. Their partner showed up unannounced, and she was not super happy to see me. It seemed like her and AJ were upset with each other. She kept trying to get AJ’s attention and AJ basically ignored her in favor of me. AJ didn’t seem shamed or trying to reassure her, just defensive/annoyed. The partner left pretty quickly.

At the end, AJ invited me to a party with their non-work friends the next week. I went and brought a trusted friend. The vibe with their partner was similar to the previous time. My friend’s take was, “The vibes were weird, man” and “They were giving you way too much attention” and “They’re really intense towards you.”

So, I don’t like how things are going. Nothing has really happened and it’s possible that it’s all in my head. But I know other people see it too. I felt concerned and anxious from the beginning, and that’s gotten worse instead of better.

My question is, what do I do? Do I apply at this job? If I go back, AJ would probably be my supervisor again. And I feel like they’d make that happen. It’s a really small team, like less than 10 people, so I’d definitely interact with them a lot regardless.

Regardless, what do I do about my personal relationship with AJ? Should I try to talk to them? I don’t understand what they want. It doesn’t seem like they’re thinking about breaking up with their partner. If they’re trying to have an affair, they’re doing a really bad job.