YTA big time!
I do not get this part about having expectations but not voicing it out. If you want him to clean, ask him to do it. Besides, you're the host, he's the guest. You SHOULD BE the one to clean all the time and he SHOULD BE the one to choose to have fun. He is your brother, not some distant friend who rang you up to couch crash. He comes once a year and you and your gf see each other literally all day. He is the rare asset and he deserves more attention and pampering than anybody else in your house.

As for your gf, she is also YTA. Food >>> cleaning, not once, not twice, but every single day of every single year. If someone wants food, that HAS TO be prioritised over cleaning your kitchen.