I'm afraid my boyfriend is gay/bi

I love my boyfriend more than anyone I've ever loved before. He is the kindest sweetest most special person I have ever met, he treats me better thAn I've ever been treated by anyone. PeriodWe met while working together. I had a huge crush on him and let everyone including him know, but he was hesitant to pursue me. (Says he felt like he didn't deserve me or could provide for me what I deserve and that I was out of his league).Eventually says he got the courags to ask me out. It's been magic with him. I fell hard for him and he fell even harder for me.A guy coworker of ours that had a crush on me had mentioned that my boyfriend might be gay when I had initially told him that I has a huge crush on him(my bf but before we got together). So after me and my bf started dating I brought it up to him about what my coworker had said and asked if he was gay or bi.He said he's experimented once or twice in that past but that there is zero doubt in his mind that he is anything but completely straight. When I asked about the details later on in our relationship he told me he's been with 2 or three guys. Given and recieved blowjobs( because was interested in what women experiened/being open minded) but that he swore he would never kiss a guy or imagine being romantically involved with one and that that thought sorta repulsed him. I was shocked and was shaking and feeling nauseous upon discovering this. I don't have anything against homosexuality but I can't imagine my man doing that with another man.I learned to put it aside because we were comepletely and utterly in love with one other but part of me was always thinking about it and everytime the thought sneaked across my mind I would start shaking.I couldn't let it go so I asked for more details and he finally confessed to me that he's been with three men and that one of them he had been making out at his work for months along with hooking up with him a few times. Never anal,but oral. He said yhere was a gay guy at work that was obsessed with him and that my bf was open and continued wanting to explore the idea of his sexuality. He said he was never able to get fully hard nor had he ever cum from any of his experiences and that he has absolutely zero interest in any of the guys but continued to kiss and make out and rub cocks together. I was floored by this revelation.i felt that he had been deceitful to me about his past and I'm scared he's in denial. I asked him if he has zero interest or was just open minded:not scared about possibility of being gay why he had continued kissing making out and hooking up for so long. He still claimed it never ever interested him. He says there is no remote possibility that he is even bi and that he's completely sure.I know I don't have a right to decide for him what he is. But at same time I feel like I've been lied to because he did lie to me a lot about the details or duration. If he is in denial I feel sad for him that he's afraid to tell me or himself, but it also hurts me to know he might be gay of bi because I can't deal with that.I love him more than life and he treats me better than anyone. He tells me he sincerely believes that God sent him a gift(referring to me) and he has never been attracted or loved anyone the way he loves me. He tells me his past is his past and he's made decisions just for the sake of making them and he doesn't think about the consequences. He says he does regret what he's done( I don't think he should but i am still extremely bothered by it)I'm not sure what to think or do. I don't know if I could be with a bi man, especially since he's often deceitful( about many things and often out of fear of what he's done in the past). I wish I could trust him and I wish he would tell me the truth about this situation.