There's a built-in guide already in the game itself called Lighthouse mode. It doesn't show all individual point changes from choices, but still provides plenty of guidance to get most paths.
There's more than one threesome in the game already. Off the top of my head, there's
two of them on Dual Love and one of them on Weird Triangle paths. Probably are some others I haven't seen yet.
Eve and Cassie have essentially
been friends-with-benefits or possibly even "lovers" for at least a year, but they're reluctant to acknowledge it even too themselves and embarrassed to talk about it on some paths. On the Dual Love path, they even
have sex without MC one morning because he got up to do other stuff and they woke up horny, but he wasn't around to make it a morning threesome.
I suspect on the solo paths they may break that off (which in a way could make it netori), but I'll be honest I haven't gotten far in either of their solo paths. Too happy with where things are on Dual Love for now.
Honestly though, if you only play solo paths there might not be any reason to even be concerned about that.