This is all about  you and leeteuk. Where Leeteuk propose a marriage to f(x) Krystal while you and Leeteuk are married...

 you log in your yahoo messenger and you found that leeteuk propose a marriage to krsytal and you chatted him. this happened in the coffee shop.

you don't know that leeteuk is in the coffee shop also.. and he chatted you also, seeing your facial expression...

this is ONESHOT..