WSL

it means I'm dead. WSL stands for 我(Wo)死(Si)了(Le) . When you are extremely surprised by something, you would say wsl. It seems like oh my god. By the way, in Chinese "deadly " means "extremely".

When your friend sends you a picture of a handsome man
You would chat "WSL" to her( it means OMG! He is so hot! I extremely love it)