I'm bisexual. My older brother and I am in our sixties. He has always been weird, including sexually weird, so I set him up. I know many in the gay community. One guy was strange, sort of like my brother, but different. I wasn't having sex with the guy, but I wondered if my brother would.
So, we all "bumped in" to each other at a store, after which I got lost, leaving the two of them together. It worked. It's started with my brother asking him to come over to clean his house, but Bill wanted more. After a few months I enquired of Bill and he filled me in completely.
It seems after Bill finished cleaning his house, my brother was short a little cash, do Bill offered to suck my brother's dick. My brother let him. Bill was happy about that and came back once a week, always ending with both of them sucking each other.
After a couple of months my brother asked Bill if gay people did more than oral sex. Bill told him about anal sex. Right away, my brother declared himself to be a top. Bill was good with that, allowing my brother to fuck him any time he wanted.
After seeing how much Bob enjoyed the bottom role, he wanted to try it out. Bob fucked him three times that afternoon. They're both equally happy with either role, top or bottom, but I really think my brother prefers to bottom.