Definition: In this task, you are given a Reddit post as a text. Your task is to generate a title for this text. The title should start with "TIFU by", followed by a situation that caused humor. The title should contain 7-12 words, ideally.
Input: Text: me and my mate recently started renting together in a flat and everyone is wanting to come and see how we're getting along. my sister wants to spend the night on the couch, and has the greatest idea of inviting my girlfriend over too, just to say hi as they haven't seen each other for a while.

me and my sister play pranks on each other a lot, so this time, as the buzzer for the door goes, my mate and i decide to grab some masks and the larger kitchen knives and start to scheme. oh what a terrible idea it is for us two to scheme. assuming it's my sister taking the lift up, we run down the stairs leaving the door to the flat slightly ajar. we press the buzzer on the door, make some silly voices to throw the visitor off, then run back up the stairs, knives above our heads, burst in through the door to see... not my sister.

my girlfriend is huddled in the corner, shaking and having a massive panic attack, as she thought me and my mate were dead, and the murders were coming to finish the job. the following half hour was spent calming her down and apologising more than i ever have before.

TIFU By triggering a panic attack in my girlfriend