My best friend bought me an "engagement ring" and acts like we are in a relationship even tho we are ONLY FRIENDS?!?!

Oh boy where do I start. (scroll down to the very bottom for a tldr LOLLL)

Hi everyone. Im 21 (female) and my best friend is 22 (nonbinary). We've been best friends since literally elementary school and we've done everything together. I consider them family and someone I really do love as a friend or even a sibling. Its been over 10 years of friendship and I really do appreciate every moment we've spent together.

However ever since maybe mid high school, things took a little turn. My friend always brought up marriage as a little joke, a funny bit. It wasn't uncommon for people in my school to "marry" their bff and from talking to others, its also common. The whole "marriage" bit is just saying "oh hey my bff is literally my wifey hahaha mwah mwah let's go do random shit". Really it was nothing else. And a lot of people see it as nothing else.

Im Bi and my bff is aro ace (basically i would explain it but just do a quick search and youll see the definition). We've continued this marriage bit to this day as a funny bit, but obviously it doesn't mean anything to me. I want to get married to someone who I love romantically, NOT my bff who doesn't have feelings for me nor do I have feelings for them because they are aro ace. I SEE THEM PURELY AS A FRIEND OR EVEN FAMILY. BUT lately they've been presenting me to new people as their actual wife or fiance which is...not totally weird but a little odd. Then they said they would buy me a ring and I thought aww its a friendship ring how sweet!

Except it was a engagement ring. Over $500. The proposal was in public at a art museum. And it sucks because they had told me it was an engagement ring but I really thought it was a joke, an extension of the original marriage joke. I felt off, akward the whole time. Luckily the museum was COMPLETELY empty so nobody saw it.

Now they want to have an actual wedding ceremony with friends and family. Outfits and food and everything. They keep asking me how my family feels about our engagement, how we are finally fiances. I laugh it off as "oh they dont care" because why should they its just a joke? Right? Its still a joke, right?

Now they want to spend every anniversary of our engagement together as if it was an actual event. They seriously want to get married. One day when we were in the car going to get my septum pierced, I was talking about giving up on dating in the mean time because I had a lot of personal issues I want to resolve before getting back out there in the dating pool. They seemed a little...annoyed? They said something along the lines of "Well how are you gonna tell them you're already engaged? Will we have to get a divorce or what?" At first I laughed it off, but I took a moment to really think. Why were they being so serious about this? I told them "Who cares? We aren't seriously engaged. Its just a funny bit. A joke. We'll get 'divorced' then." After that we just moved on. What baffles me is why they really think I will have to tell my future partner or somebody I go out on a date with this: "oh hey sorry I forgot to mention im engaged to my bff so idk if we can really date! Guess ill have to divorce them!!! >_<". I dont know anymore if they were being serious or joking.

Anyways, I had brought up how uncomfortable my friend has been making me lately to friends and family and they fully agree they have taken the joke too far, but I haven't been the best as putting my foot down and telling them to stop. Im a people pleaser. I dont know how to say "please dont" because I will literally become a puddle of tears if I make someone upset or mad. I agreed with them and I would either a) talk to them about it and tell them to stop. Or b) try and avoid playing along with the marriage jokes or anything of that matter. Obviously option A would be hard to do as a people pleaser and someone who avoids conflict, so I opted for option B until I got the guts to say something.

So far its been fine. They are pretty adamant about me moving in with them despite me being super financially unstable. Ive been able to avoid that conversation for the meantime. We've been wanting to move in together but with everything ive been feeling and going through I just dont think I want to live with them anymore. For my sanity and for wanting to not hate them.

Now a week or two ago, they stopped by my workplace and we chatted for a bit about life. My sister might start a family soon so I talked about it, then i mentioned how I didn't want kids now. I explained my simple reasons and kept it as is. Then my friend said "Well what about our kid? Our foster kid?"

PAUSE. OUR KID?! I had to take a mental screenshot before trying to wrap my head around it. For context, they have mentioned time and time again they want kids, specifically foster kids. Ive been super supportive of the idea and told them I'd be there for support! But I NEVER mentioned raising a kid with them. Ever! So when they said "what about our kid?" I quickly shut it down and said "haha no. YOUR kid. Not mine. I dont want kids. That's yours to raise." I quickly changed the topic and showed them vacation photos, but it was no use. They kept interrupting me saying "but our kid? Our baby? What about us, our kid? But but!" FOR 5 MINUTES STRAIGHT. I WANTED THEM GONE OUT OF MY SIGHT AT THAT VERY MOMENT.

Eventually they stopped mentioning it but clearly they were bitter about it because i would say no over and over again. I just didnt say a thing and kept it as is. We parted ways eventually and after that I was so angry, so upset! Can they not see i dont care for kids? Or for anything related to the matter?! And I had been vocal about it too! For once I decided to put my foot down and say no and it was pointless!

Honestly I dont even know anymore. I questioned if my friend maybe has feelings for me, but they are aro ace so they couldn't right? Maybe the line between friends and something else started to blur for them but not for me. Maybe im at fault for entertaining the marriage joke because I saw it as an innocent joke and nothing else, but they saw it as an actual commitment to each other? I really dont know. Other friends I have say they are being too possessive too obsessive about me and who I spend time with because not too long ago they kept pressuring me to put them and a new friend I have into a group chat with me so they could know everything about what me and my new friend have been saying. I shut the idea down. Before this, my friend got mad at me for saying im more tired after we went to a concert, but I didnt see it as an issue. They said I was trying to one up them, basically saying im better than them or if my problems are worse than theirs. And to be honest, I feel like i have to perform for them everytime we hang out. I cant show a single frown or neutral face when we spend time together because they begin to panic and constantly question my happiness, asking if im okay or if I need support. Basically they coddle me, treating me like a fragile toy. Im not fragile. Not anymore. I dont think they've realized ive grown up, im not the same person I was when I was a teen.

But yea. That's it. Well there's more, but if I keep going it might never end.

I love my friend, but my love only goes so far. I feel lost sometimes with how to go about our friendship now. Thanks for listening :<

TLDR => friend acts like we are in a relaltionship and went as far as to buy me an engagement ring and introduces me as a partner or fiance much to my dismay and dislike for it and even wants to adopt a kid together even tho i dont want kids. and i think im the problem because i struggle to form boundaries as a people pleaser.