How does this level of compartmentalization affect you and your relationships?
At the time -- I let them each know I was seeing the other, and gave them contact info. So if they wanted to talk and form their own friendship or whatever they could. They didn't -- they were cordial the few times they had to interact but not into more than that. But I'd done my job in terms of providing contact info.
It worked out fine -- in terms of keeping things separate. One was LDR so geography was helpful in keeping things separate. BF1 handled jealousy on his own without telling me much about it. BF2 struggled with jealousy and fussed at me some but eventually got over it. Everyone is different.
It also worked out challenging -- because after a point I was tired of the compartmentalization and things had to change around and then the geography (which previously had been a boon) was now a PITA. BF2 and I broke up and faded to friends and then faded to memories. It was a good experience.
But I wouldn't want to compartmentalize for long haul today. At the time having (multiple non-primary) as the open relationship model
was great. I want something else now. It is entirely possible for time to pass and for me to want that model again, though. People are not static -- even oneself.