With the Main Girls, you can always choose what happens, as in, avoid and have it never happen.So I don't want to get into definitions or anything like that, all I want to know is regardless of if it's main girls or side girls will all instances of any other dudes besides the MC being involved sexually be avoidable as in it doesn't happen or is it going to happen on some level no matter what. I just want to know if I should bother or not.
With the Side Characters, you basically always decide what will happen as well, but I can't promise that everything will be avoidable, because designing alternative story paths for each different scenario would be a lot of work. So, sometimes their events might only be skippable.
However, currently 99% of the content is between the MC and the girls, as I mentioned before, there's 1 skippable scene at the beginning, and in this update you can choose to send a girl (Side-Character) to another dude or keep her for yourself.
At the end of the day, this is a game mostly focused on corruption and the sharing aspect is supposed to be a tool the MC can decide to use it or not.