This game consists of getting two parts of the key.
First Part of the Key
This part is described to you by the fly. He shows you the two things you need to do before he can get it.
~Grab the brush off of the tub, and use it to pry the boards off of the small window above the door. ~Grab the plunger from next to the toilet. Use it to block the spider's escape from the vent above the tub.
Once you do these two things, go back to the fly and click on him. He will fly out the window, grab the first half of the key, and give it to you.
Second Part of the Key
This half is more about collecting and combining.
First, collect:
Toothbrush and Dentures on the sink. Metal Plate in the hopper (top part) of the toilet. Dental Glue in the cabinet. Control Valve from the left side of the toilet.
Then, combine:
Metal plate + Dentures = Small Saw Small Saw + Toothbrush = Handle Handle + Dental Glue = Handle with Glue Valve + Handle with glue = Second part of the key
Combine the First and Second parts of the key, go over to the door, look through the keyhole, and voila! You have escaped the dreaded bathroom!!