Let's be honest here, if this story operated more on things that make sense and are closer to reality, particularly with regards to choices affecting relationships and lewd scenes, then it would probably be a lot better. There are many moments like this for me, and one such example is the decision in Ep 2 to go back to Maya or stay at the party.
By choosing to go back to Maya you don't dance with Sage which, I guess, means he sneaked past her on his way out in order to avoid her, but what's to say he couldn't also dance with Sage before going back to Maya? It's not like he's on a time limit and his chance to dance with Maya will be gone if he doesn't get back by a certain time; is he Cinderella?
Let's say that he's called over for that shot battle at around 10, it probably wouldn't take him long to get to the DIK mansion, 10-15 mins maximum, then the 3 shot battle probably takes about 5 minutes. He says he'll head back to Maya but on his way out he's grabbed by Sage who pulls him onto the dance floor and this, plus them making out, probably takes up about 5-10 minutes, which means he could be back at the dorm well before 11 and Maya would surely still be up. Hell, the MC could also fuck Sarah and have plenty of time to get back to Maya, dance with her, then finger her.
However, game logic dictates we must choose even though, realistically all these things could be done and you could simply leave it up to a different sort of player choice. Instead of automatically not dancing with Sage, the MC could be on their way out when Sage grabs them and then it's up to the player to choose to do so or not, then they encounter Sarah, or Melanie, or Riona, and once again get to choose between having sex with Sarah or not. It's a much cleaner system, in my mind, and one where you're not scratching your head so much wondering why certain things don't make sense whether you did or didn't do them.