Cup and Jade's House

Cup and Jade stayed in a corner semi-detached house in Desa Senadin. The house had 3 bedrooms, but there were only 2 of them living there.

One morning, Jade woke up and went to the bathroom to brush her teeth. The bathroom was right outside her bedroom door. After she had brushed her teeth, Jade noticed a sandal and a slipper outside the bathroom door. They belonged to Cup, but the ones outside the bathroom weren't a matching pair.

When Cup woke up, she went to the bathroom near Jade's room. Cup usually went to the other bathroom, as there were only two of them in the house. Jade was sitting at the dining table.
Cup saw her slipper and sandal outside the bathroom and asked Jade about them.
And Jade replied that she was just going to ask Cup why she put her footwear outside the bathroom.
Cup said, "it wasn't me."
They both looked at each other and rushed out of the house.
After they had calmed down, Cup and Jade went back into the house and looked at the footwear and talked about it calmly.

Then Jade pointed out the mop nearby and lifted it up. There were insects under it, as it had been left there while it was still wet. Jade asked Cup why she left the wet mop there without drying it out first.
And Cup replied, "I always thought it was you. I haven't mopped in months."
And Jade hadn't mopped since the beginning of the semester...