Is it normal for some straight guys to want a gay guy to give them a bj?

I'm a gay guy. When I was a sophomore in high school, I wasn't out at all. But I think one of my straight friends figured out that I was gay. He walked home with me one day after school. We were hanging out in my room, and I was laying on my bed, while we were just listening to music. All of the sudden, he got on top of me, straddling my chest, and pushed his crotch in my face, and told me to suck it. I thought he was playing, so I opened my mouth, and told him to put it in. He said, "No, I'm not hard right now." He sat back down in the floor, and we just started listening to music again. A few days later, he walked home with me again. Once again, while just hanging out in my room, he straddled me again, and did the same thing, and told me to "Suck it." So I opened my mouth again, but actually, I was hoping he was going to let me. He told me to put my pillow over my face, I'm guessing so that he couldn't see my face, and maybe just think about a girl, I'm not sure. So I held the pillow over my face, and opened my mouth. He said, "You promise you won't hit me if I put it in?" I said "No, I won't." Next thing I know, I felt his dick in my mouth, on my tongue, so I closed my mouth. He started basically f**king my mouth. This was the first time that I had ever done anything with a guy, ever. He kept going until I felt him cum in my mouth. He pushed his dick all the way in when he started cumming, making me swallow. When he was done, he hurried and put it back in his pants, then got up. I almost couldn't believe that I had actually given my best friend a BJ, or that he actually Let me. I asked him if he actually came in my mouth, and he said no, that he didn't. But I know that he did, because I felt it, and tasted it. I thought he might be gay too, but it turned out that he wasn't, it was just that we were both 16, and 16 year olds are just really horny, and he couldn't seem to talk to girls very well, because he was really nervous, and didn't know what to say, because every time he tried, he seemed to get shot down. He told our other best friend what he did, I found out later. I know, because about a week later, our mutual best friend came with him when he came to spend the night with me. When we woke up the next morning, he left early because he had basketball practice. When he was gone, our other friend, that came with him to spend the night, just came out and said, "Chris told me what you did, will you suck mine too?" I acted like I didn't know what he was talking about, and said that Chris was lying! But he just said, "It's cool, I won't tell anybody, promise." I just kept denying it, and didn't do it, because I was afraid that I'd be outed at school, and that I might get beat up for being gay. Later that day, when he left, Chris came back after practice, and I kind of went off on him for telling. All he said was that he didn't think I'd mind, because he thought I'd want to suck his too, but that he wouldn't tell anyone else. I know he was straight, because he would never even touch me, but just wanted to cum. He eventually got a girlfriend, and stopped talking to me, I think because he was ashamed of letting a guy get him off. But all the way up to that, he would sometimes come over, and just randomly say that he "wanted to cum," and ask me to "suck it." I gave him a BJ maybe 8-10 times after the first time, but only when he wanted one. If I asked on my own, he'd say something like, "Stop asking, I don't want to right now, I'll let you know." Anyway, I was just wondering if it's kind of normal for some straight guys to let their gay friend get them off, because I've given BJ's to four other straight guys since, that I knew for sure were straight, that just wanted to use me to get off, which I really didn't mind. But, has anyone else known other straight guys that have done this with their gay friends?