Locked Out!

I came home the other day thinking that my housemate was back and was sleeping.
He just came flew back from KL about a week ago, and he's extremely jet-lag. waking up at funny hours and such.
Anyway I decided to latch the door as I always do.
After that, I went and took a bath, and when I was showering, I had a loud clanging noise, and I thought my clothes feel off the rail or something, and I drew open my shower curtain and peered out, and didn't see anything unusual, so I ignored it and continued showering.
After I came out from the bath, I realised that my housemate's light was on, and he told me that I locked him out! and he had to use some sort of manouevere to open the latch, which he says it's a secret. hahaa so funny. I'm exceedingly evil! *evil grins*