Is my friend giving off lesbian vibes?? 😬🤷

A little backstory before I begin:

Let's call her "J"

She's actually my boyfriend's friend. Or at least that's how we met. They worked together and have known each other for about 3 years. I've only known her a year, starting when I started seeing my boyfriend. We aren't really close, and see each other maybe once every other month or so. Same thing with her and my boyfriend.

She and her fiancé have a very open relationship, and the way it's described, it sounds like they're swingers. I'm totally cool with this, they can do whatever they want in their relationship. She has some particular "needs" that her fiancé doesn't meet, including anal, a lesbian fetish, and some other ones that I forgot.

Personally, I'm pretty much straight. My boyfriend and I are very monogamous, and will not see other people while we're together. However, if I've got a few drinks in me, and my boyfriend is okay with it, I've been known to flirt lightly with some of our other female friends on occasion, and do innocent "lesbian-ish" things for the sake of the excitement factor in the middle of parties or get-togethers. (Seductively share food, feed/be fed by another friend, and once a small kiss) Of course all the guys love it and it's always been fine and all in good fun for all involved. No big deal. Just "heat of the moment" crazy party stuff.

The last time this happened, our friend J, was there and she saw me act this way. I feel like ever since this happened, she's been giving off very strong vibes that she's into me. Every time we hang out, she gets very close to me the entire time, and makes a point to only message me and not my boyfriend when she wants to get together with us. (This is upsetting my boyfriend and making him doubt her friendship with him since she only talks to me now)

The last few weeks now, she's been obsessed with the idea of us going out together on a friend date. Of course I'm chill with it and I enjoy seeing her. We have the date set for this upcoming Monday, which is 4 days away.

Well, she's been texting me details. She's planning on us getting dressed up really fancy in formal attire and going out to olive garden. (Okay nbd) She also wants to bring me a bouquet of roses and pick me up. (Little weird, but okay) And finally, she wants to go back to her place and watch a movie. (Not a weird thing I guess, but I'd rather go to the cinema)

The whole "going back to her place" is offputting because when we first started planning this "date" like a month ago, she mentioned in passing that she'd like to cuddle on the couch with me on our date night.

I'm beginning to think she's considering this to be a "romantic date-date" kind of thing. I feel like ever since she saw me in my "party mode" a few months ago, she's seeing me as a potential side lover, and that's something I'm NOT into. She knows this though, which is another thing. She knows I'm straight, and dedicated to my boyfriend.

I'm fine with going on a friend date, but I'm really not all that close with her. This is something I might normally do with someone I've been friends with my whole life, and we just have that repore built up. She's kind of acting like we're best friends, kind of like she's jumping into a conversation that was never started. What do you ladies think about this? Is she considering this a romantic date and giving off weird vibes? Am I overreacting? How should I approach this?