Is it normal that i am a guy and gave a bj to another guy?

Let me start off by saying I am straight male. I have never thought of being with a man neither in a relationship or sexually. Saying that, the other day I went to buy a laptop. I opened the stores door to get in and it was sticky and nasty so i go into the bathroom. Its small for one, person. I walk in, lock door i turned around and and a guy masturbating. He says don't mind im just a bit horny. I wash my hands but i keep staring at him doing it. He asked jokingly if i wanted to blow him and i dont know why but i said you want me to? He takes his hands of his penis and looks at me. I go, get on my knees and just start blowing him. He tells me hes not gay but a bj is a bj. I was enjoying a lot. I had my hands on his hips so i can go back and forward harder and faster and after about ten minutes takes it out of my mouth tells me to open, jerks off, and a few seconds later cums in my mouth, i swallow. We exchanged numbers but i didn't think he would call me. About 2-3 days later i go to his house to see a boxing fight. His girlfriend was there. I felt so bad and ashamed and yeah.
..After the fight she leaves and we stay. He tries to make me blow him but I really did not want to. He takes it out and comes close to me and i dont know why but as soonest it was close enough i start blowing him again. He gets me naked and we walk upstairs to his room. We get on his bed and he tells me to get in doggy position. He sits on front of me, puts his hands against my lower backs and starts doing my mouth, slowly but still doing it. he tells me to lay flat on my belly and i do. He keeps doing my mouth slowly and grabbing my ass with both hands. I enjoy his hands grabbing my ass and when tells me to suck on his finger i do. He goes back to mouth doing me and starts massaging my asshole with the finger i licked. I was scared. But he didn't do anything else. I've blown him about six times since. And he has finger my asshole on 2 occasions. I've had many girls and I am confuse to why I do this even though I don't want to. I do enjoy it but I don't wanna do it yet i still do. any Advice?

And no i won't try anal a finger is enough.