TIFU by asking my friend for a hookup

Technically Sunday**I dated my friend last year for a couple of months, and we broke it off. Emotional incompatibility and distance being the issues. We became friends after. Well, earlier this year, we celebrated their mom’s birthday. I was the only other person invited other than the mom, her husband, and my friend. They bought me a cute nightie later that afternoon and we hooked up that night. They told me they’d hooked up with two other ex’s who they’re friends with. Which is fine, we test regularly. Then they started dating these two girls. But one they broke up with kinda soon, because she was emotionally immature and weird. The other girl, is married. Polyamorous. My friend is pansexual, and was exploring sexually with me and other friends and these two girls. I’m not judging, I think it’s fine because there was consent on all ends. But anyways, I met this girlfriend and she’s amazing, I really thought she was great for my friend. I started to get close to her. I met everyone’s friends and it was a good time. A lot of the friends are polyamorous. So, needless to say, putting all these puzzle pieces together, I thought my friend was poly. When we have hooked up and when we dated, they were a safe person, no judgment, compatible in that way. I’ve been single on and off since dating them. But mostly single since last winter. I don’t know why I didn’t clarify if they were polyamorous. I asked if they wanted to hookup sometime, because it was a safe connection IMO, and I thought that through getting consent it would either happen or not, but that it was fine to ask. It was not. My friend is the only monogamous person in her triad with this girlfriend. They were immediately was like, what makes you think that I’m available and I’m hurt, how could you ask that, etc. And I was like, wait, I didn’t know you weren’t! I apologized profusely to them and their girlfriend. I told them I couldn’t apologize enough and that I truly meant nothing weird by it. I thought it was something that we could discuss and maybe do, because we’ve discussed stuff like this before. The girlfriend cut off the friendship saying that she didn’t believe me, and even suggested I was jealous. But I really like both of them together, it was never a problem for me, I was happy they found someone that they liked. But I thought that was just one partner out of maybe more in the future. I told her I respected her wishes and that I would remove myself from the relationship with her and my friend. I unfriended everyone and basically said, I’m sorry, I truly didn’t know, I should’ve asked and I didn’t, this is a weird freak thing on my end now, but I am truly sorry. A couple of the people I met through them asked why I unfriended, and I said it’s a private issue and that it was okay, and nothing against them. And they were understanding and thankfully not offended. But yea, I blew up my friendship.

TL:dr- I blew up my friendship by asking for a hookup thinking it was safe to even ask, because I thought my friend was polyamorous and open to stuff like that. Their girlfriend was polyamorous and even a bunch of mutual friends, but my friend was absolutely not.