He was my half brother and he lived with his mom in another town so we didn't get to play much. I'm pretty sure my boy dick wasn't his first. About the time we got going he was drafted and went to Vietnam. We never had a chance after that and he died in the 80's.
I'll bet your older brother felt good to be fucked by a slim, boy cock. Of course, it would probably be be a few years before he appreciated that being broken in by a slim cock is a lot more comfortable than being popped by an adult cock.