I was one of those guys who started jerking off with friends in my teens as my sexuality was developing. My friends and I would get together and jerk off to "men's magazines". You know, those magazines you could only find on 42nd Street in NYC where I grew up. These were the nudie type with women with big tits, and very hairy bushes.
My best friend in that group was a little older and could buy them. One time he and I were in his room and he asked about jerking each other's cocks. At that age, anything was sexy so we did it. One day he asked if he could suck my cock, and so none of my girl fiends would do it, I agreed. Back then I could cum many times at a session so it only took about 5 minutes until I shot off.
I found out later that he was getting together with other guys I knew and decided to get us all together for a group jerk off session. The kid across the street from me was one of those guys so we'd get together and play with each other, eventually moving on to frottage, with sliding our cocks between another guy's thighs. The next step, of course was sucking each other. My neighbor and I were hooked together and his cock was thicker than mine and pointed up. We had agreed that if anyone wanted to take the load we could but if you didn't then say no and the guy would just shoot it on a tissue. Well, when my neighbor was ready I said I'd take it. His cum was fantastic and I swallowed every drop.
Girls came with a lot of drama, but my circle of friends were easy and fun. That's when I knew I could be with a guy or a woman. We didn't call it "Bi" then but that was the start for me!