hey guys i'm new here, i have a question (long story)

Hey guys, it took me a lot of courage to sign in a LGBT community-as you can se I'm a Q at the moment, unsure if i'm bisexual or not. Excuse my English if there's anything incorrect. I'm a Korean girl living in Seoul, but since 1. there aren't any websites in my country where i can ask these kind of questions 2. i have a fear that someone will notice who i am based on my stories 3. i somehow got to know emptyclosets a few days ago while Googling about sexual orientations, and you guys were really generous to one another, I made my mind to come here again.

Okay here's my story. In Korea most of the schools are a Girl's School/Boy's School-i mean a lot of schools are divided after elementry school until we go to college. As most of the kids, I also graduated girls' middle and high school. I didn't know back then that I had a crush on girls, but come to think of it I think there were a few times that i had had a crush on a few of my best friends. And I noticed recently that i have been asked by a few of my friends, but not in a serious way(like a joke), in the past 10 yrs if i was dating my best friends(it was one at a time, but wasn't just one person, I think it was about 4 throughout my life) because I was so close with them. Maybe it looked like dating, i don't know. There was nothing sexual in betweeen my friends no kisses, no touches, but from time to time my friend and i texted all night long and there were some 'I love you's and 'I miss you's. But back then i've never thought of it in this kind of way.

After 6 yrs of middle and high school, i came to college with great expectations of meeting boys. It's been 4 yrs since i've been to college and i've dated 3 guys. Currently dating my boyfriend for 3 yrs. I think of him as my true 'first love' (sorry for the past 2 guys). I love him a lot, I have had sex with him, still attracted to him.
Here comes my problem. I've started to question my sexual orientation. The experiences i had when I was young, has kind of started again. My best friend started to text me 'Love you, sweet dreams' and this time i couldn't condradict my thoughts saying this isn't at all different with what i do with my boyfriend (it was only the physical part missing) So I've looked back upon my school days and started wondering if this too was love all along. Just as realizing my 2 last boyfriends turning out to be just a 'boy' friend, not true love, I thought to myself, it could be the other way around. That is to say, even though I had not defined my relationship with my best friends a girlfriend-girlfriend relationship, it could have been love. Through my college life, two of my friends openly came out that they were gay (both of them are male) and that's when I realized there were these kinds of love. If I were in the US like most of you guys here, it wouldn't have took me so long to realize it, but here in Korea, we have just started to discuss LGBT issues not long ago. It's such a closed society that there is only ONE gay celebrity in my country.
Yesterday I asked my boyfriend, not in a serious way, 'How would you feel if I were bi'. He said without any concern 'that is totally fine with me as long as you don't leave me.' And even said to me, 'it would be more than okay that he could share my feelings with another girl.' I know from my instincts, that the answer would have been totally different if this issue was to do with another man. I think that he didn't consider of physical love(sex with a girl) though, since it is hard to imagine for him me sleeping with another girl. I didn't have the guts to ask that question since that definitely would have become serious.
He didn't look serious, but also I felt that his words were true. Now i am confused if that was a permission that i could meet a girl. I have feelings for my best friend, but i would never do anything to scare her away from me. So the only way I can think of is to meet someone through apps (i heard from my Gay friends this is the most common way to meet the same people in Korea).

To make my long story short,
1. Am I bisexual? I've never thought of kissing a girl, but realized that I do have feelings.
2. What should I do with my boyfriend? This really sounds selfish to me, but I don't want to lose him, but at the same time I want to find out more about my other sexual orientation.
3. I know that this is unforgiveable if it was another guy I had a crush on, or going on a dating app and meeting another man. This, I would really have to let my boyfriend go. As with girls, my boyfriend said he is okay if i was bi, even said he would be totally okay if he shared me with another girl. But even with girls, I feel like going behind my boyfriend since i asked this question without seriously coming out.

Thanks for reading this long story you guys.