Huh... I actually know the sex scene in FSN that OP is talking about and it's not actually that OOC.
While I do admit it comes out of left field and a participant isn't exactly eager, the "expanded universe" does explain why it has to happen the way it does(though Realta Nua did replace that scene with MANADRAGON). That particular route does have at least one more sex scene which is basically pointless and gratuitous and there's one more during the final route as well but overall the sex scenes in FSN do serve the story on some level. Eliminating them doesn't detract from the story, but having them in adds to it (UBW sex scene adds to the relationship between two characters and HF sex scene(s) are milking the sympathy cow for all its worth).
Now compare that with the sex scenes found usually in VNs and you'll understand why I'm far more lenient with FSN...
While I do admit it comes out of left field and a participant isn't exactly eager, the "expanded universe" does explain why it has to happen the way it does(though Realta Nua did replace that scene with MANADRAGON). That particular route does have at least one more sex scene which is basically pointless and gratuitous and there's one more during the final route as well but overall the sex scenes in FSN do serve the story on some level. Eliminating them doesn't detract from the story, but having them in adds to it (UBW sex scene adds to the relationship between two characters and HF sex scene(s) are milking the sympathy cow for all its worth).
Now compare that with the sex scenes found usually in VNs and you'll understand why I'm far more lenient with FSN...