You decide to take the chance, and eat the slice of cake, due to how hungry you have gotten, and just shove your fork into the cake, taking a piece from the slice. You then use the fork to take the piece up to your mouth, and eat the piece you took from the cake slice. It was perfectly fine, and you finish the rest of the slice.
Once you were done, you decide to put the rest of the cake in the fridge next to the counter. After you were done cleaning the table, you wait for mother to come back. Unfortunately, you nap, while waiting for 3 hours, which means something must have happened, so you decide to look for her yourself. The first thing you do is get out of her office, into the hallway the guards lead you through, and find that it was entirely deserted. Meaning no one was guarding the elevator, or the other rooms.
You rush to the elevator, and open the doors to them by pressing a button that leads to the floor your on. The elevator opens, and you go inside, finding a bunch of floors that contain the monster girls your mother has had stored away. Knowing your mother, she was probably in one of them, so you decide to find her, by checking each floor the elevator has.