Spoilers: Yuri made that cake.

And since he made that cake, and helped with the set up, he's hovering around.

With everything that's happened lately he's been a bit preoccupied, but one wouldn't know that from looking at him. However he hasn't let Anton down since that one time he'd shown up late, and has been doing his part to keep the hotel running smoothly.

Yuri seems in good spirits enough when people arrive and he cuts the cake, handing out pieces.