You and Zack know each other for about 4 years already, you are best friends and live together. A few weeks ago you've noticed his mood change around you. Sometimes he's the sweetest on earth and the next second he's cold and rude.

You knock on his door. "Zack? Can I come in? I need to talk to you." you say with a hesitant voice. You hear a groan from the other side of the door. "fine come in." he says and you open the door.