Something up their sleeve

Alicia & Brandon were napping in the room on Saturday when grand-uncle & aunt came to visit. We were chatting away when I heard some noises coming from the room. (Mummy needs to have sharp ears, you know?) When I went up to take a look, Brandon had his pants & diapers removed. When I asked him what he's doing. This was what I got:

Mummy: "What are you doing?"
Brandon: "I put-put..."
Mummy: "Then why did you remove your pampers!?!"
Brandon: "Alicia jie-jie take out my pampers."
Mummy: "Why did she take your pampers? What are you trying to do?"
Brandon: "Put-put must wash pi-gu what..."
Mummy: "Why didn't you call mummy?"
Brandon: "Jie-jie wants to wash for me."

Argh.... dun know to laugh or get angry. Alicia explained in the end that they tried to go into the toilet but decided against it as the floor was slippery. At least they understand...