What should I do about my guy best friend getting mad when I told him I don’t like him romantically (he has a GF)

so I am a senior in high school (nonbinary 17) and my guy best friend ive had since my fesh year of high school ill just call him B (M 17). now for context me and B have been extremely close and yes i did have a crush on him my freshman year that he knew about before I got with my long time girlfriend ill call girlfriend (F 17). towards the end of freshman year we did have a falling out because of his choice in who he was dating as his girlfriend royally hates me. over the last three years I’ve cut friendship off a couple of times because of things relating to him disrespecting me and girlfriend by texting her and asking if she was happy in our relationship which made her uncomfortable and for dead naming me over text (at the time I was still figuring things out and was a trans male). now all the times before he apologized and told me that he was in the wrong and shouldn’t have done that but last time I cut him off was when he lied to me about who he was dating (the same girl from fre year who had broken up with him off and on and all out hurt him) and the reason we became friends again was actually because me and my Girlfriend broke up and I realized all the people I had hurt so I started apologizing too all those people and the one i realized I hurt was Him because who am I as a friend to get upset by who your dating? well that was my thought process. well anyways we because friends and he did apologize for lying to me about being back with her but he did inform me they were still dating and I said that I didn’t care, I just wanted to be his friend and felt bad for hurting him. fast forward a week (his girlfriend was off at basic training for the military two states away from us) and we started accidentally falling asleep on call and then two weeks later we were falling asleep on the phone on purpose while being on face time all the time and talking all day. we were cooking, cleaning, sleeping and doing our separate hobbies on the phone together and on the second week of talking again he made a comment about how we used to flirt to freshman year before we were in relationships and then he attempted to flirt with me and I laughed then said “you have a girlfriend stop” and he kept trying to and I snapped telling him “no B you need to stop, you have a girlfriend and i refuse to let you emotionally cheat on her with me especially since she absolutely hates me” and he got all sad then I told him I was hanging up and going to bed, like five minutes later he called to apologize then ended up hanging up then a couple nights later he asked me for my honest thoughts about him dating his girlfriend (he did tell me he wanted to propose to her) and I told him honestly I didn’t like that they were together because she and him had broken up three times before this time of dating and she constantly made him sad and caused him having problems, he said he understood and we went about our night but it was a few days ago where we got into a big fight and he has since stopped talking to me. the fight was because of him Saying we should go to the gym together he said “hey we should go to the gym sometime“ I laughed and said “no I’m not going to the gym” and he said “what’s the matter don’t want to get strong“ and I said “no I wasn’t to go To the gym but not with you” and he said “well that’s rude why not me” and I told him “because you know how mad your girlfriend would get knowing your at the gym with me” and he said “it’s fine I’ll tell her I’m going to the gym with my guy friends“ and I said ”that’s weird And I don’t want to be apart of that” and he said “wow and here I thought you had a crush on me“ and I said “I don’t, I want to live out my life and become a witch in the wood and have urban legends made About me” (he knows i like urban legends and we had just been talking about Them a bit before) and he got upset then hung up and a few minutes later texted me that it’s best if we don’t talk anymore and When I questioned it he said it’s better for the both of us and said its For him and his girlfriends relationship and he will text me when they break up then blocked my on instagram and ever since then I’ve been confused because he has a whole girlfriend who he wants to marry but he’s upset when I say I don’t like him romantically? My sister said we we’re basically in a situationship, my brother thinks he got his ego hurt when i rejected him and that he’s inlove with me but I’m confused because why would he date Her again and want to get her and engagement ring if he liked me? I don’t know but I’m posting this because I’m desperate for an outsider opinion on this situation.