Originally Posted by
Duck1981
I wasn't aware that someone needs to stay every night in a hotel to get a credit as it would otherwise violate T&Cs.
You don't necessarily need to stay every night. But you do need to physically enter the room.
I wouldn't call this an ethical or moral issue (or attach labels like "fraud"). It's just a question whether the hotel will credit you the nights. If you don't physically enter the room, there's a very good chance it won't.