help me solve my current situation sos

OK. my name is sam (she/her) and i have had this best friend for about 1 year (his name is Gui).

I never questioned myself about what I thought about him because when we first met I was dating a girl for a short time, and he also had his girlfriend.

we met at school, the story is very simple but very important to contextualize everything. well, I've always had a group of friends since kindergarten (about 4 boys), but they changed shifts and we moved away, but I was resigned to the situation, because that happens. now in 2020 with the pandemic my class mixed with another and I met a few more girls who were soon part of my group of friends, so it was us, 8 girls. my face-to-face classes came back in the middle of 2021, and I recognized a lot of people I didn't see in time (including the 4 boys I mentioned before), but since we had stopped talking, we just acted like we were complete strangers. so far so good, until a friend of mine started talking to them and by pure coincidence we started talking again. Maria, a girl in my class, knew Bill, and this same friend that I had mentioned before was introduced to him, because Maria said he had HALLS, and my friend went there and asked for him. Gui was in the same class as the boys, so he ended up joining our group of friends. he and I got close right away, we liked the same things and our mood was very similar. I only started talking to him because he always had HALLS in his backpack, and I always asked him for some candy. ok ok, now that you know the history of how we met, let's go to the present day.

my relationship was really bad, really, it was going downhill really fast, and who helped me? he! the problem is that he was getting closer and closer to Maria, until we all (me and my friends) went to the cinema together, and in the middle of the section he, Maria and my friend Sofia went out to the mall market to buy chocolate. when I was alone with him, he told me that the two of them were making out, and I was kind of upset that he didn't tell me, but I showed that I was happy, because they were a really CUTE couple.

the days went by and he always spent the breaks between classes in my room with Maria. two months ago (I remember that day perfectly), I started looking at the two of them with different eyes, and it wasn't anger or remorse for not saying anything to me, it was something very similar to jealousy. this feeling grew every time I looked at the two of them together. I, as a righteous person, decided to pay attention to my feelings and realized that I was liking him. being a fair person, I told my girlfriend that I thought I was liking a person (at this point, we weren't talking often anymore), and two days later she broke up with me (I was super understanding, I was already expecting this so no I was just as upset as I thought I would be). I didn't tell him that we broke up because I thought my ex, who is a friend of his, had already told him. when I was 100% sure that I liked him, I told Bela, my other friend, that I liked him, and that since he supposedly wasn't dating Maria, I wouldn't have that much problem, but that's when everything changed. Bela told me that they had been dating for a month, and she was still surprised that I didn't know (Maria told her that day). I was really hurt and mad that my best friend didn't tell me he was dating. one day, Sofia, my friend, had the idea to say that someone in my class was liking him, and a week later she said it was me (with my permission). in the last few days, after what happened, he's been really affectionate with me, showing affection publicly (which he doesn't do) and calling me cute and pretty all the time.

his girlfriend treats him super badly, she takes his cell phone and stays with him all morning looking at his messages, his gallery, insta, EVERYTHING. in lab class last week a girl in my class asked her "you're dating that tall boy from class F, right?" and she simply replied "no, we didn't even kiss". I died of rage, I couldn't believe he was being tricked like that. he is very sweet to her, even too much, and she treats him super badly. her contact on his cell is as "babe" and hers is as "guilherme". rumors are spreading that they broke up, but he hasn't told me so far.

I wanted to know if it's worth talking to him about the things she does to him and he doesn't notice. and if I did, what how would I do it? please i really need help!