Hmm, so in the headmaster event you have to either allow him to dominate the threesome or—if the MC takes control—start having gay dreams every night. Not really keen on either option.
In the girlfriend/best friend choice I stuck with the girlfriend because there was no real reason to switch (it's a blind choice), but apparently that ends all content with the best friend and there are no further events with the girlfriend either.
Went back and checked the path with the best friend instead, and apparently the girlfriend has been massively cheating on the MC, but we only learn about it on this path? So the girlfriend path is basically a trap, leaving the MC with a cheating girlfriend and no more best friend?
If the MC breaks up with the girlfriend, she'll still be available for chats at school and dates on the weekend. That should probably change.
(The MC's attitude to his own cheating is still inconsistent, constantly cheating on his girlfriend and then suddenly being opposed to it when it comes to his best friend, but we've been over this already and presumably it'll be smoothed out eventually.)