That feeling when your crush says, “I love you”, but after you elatedly confess your feelings, she/he continues, “I mean as a friend…”
はしごを外す (はしごをはずす, hashigo wo hazusu) is an idiomatic expression that literally means “take off the ladder”. Figuratively, it indicates the act of “betrayal”: to encourage someone to do something first (putting a “ladder” for them), and then show disagreement with what they do (take off the “ladder” suddenly). Here is an example:
Friend: Actually, I don’t like him. What do you think about him? [putting a “ladder”]
You: Yeah I really hate him, too. He is so self-centred and f*cking annoying!
Friend: Wow, I didn’t think that much! [taking off the “ladder”]
Here, your friend puts a “ladder” that leads you to shit-talking, and after you confess your candid feelings, suddenly takes off the “ladder” (on purpose or not). In that situation, you’d feel “はしごを外された (the ladder was taken off)”, meaning you are betrayed by your friend and feel abandoned.
In a more formal context, はしごを外す also means “to pull the rug out from under someone”, that is, to suddenly take support away from someone. For instance, if the government encourages researchers to work on particular topics with providing sufficient findings, and in a couple of years, stops the support because it regards them as “non-essential” anymore, that’s a typical act of はしごを外す (taking off the ladder).
ex.1 [Example of when your ladder is taken off]
Your Crush: I love you! [putting a “ladder”]
You: Really? That’s so great!!!! I love you too since I met you for the first time!
Your Crush: Wait, what? I mean as a friend… [taking off the “ladder”]
I was very excited because I was appointed as the project leader by my boss. However, the project was cancelled suddenly and now I feel “the ladder has been taken off”.
Synonym: 裏切る (うらぎる), betray
Synonym in English: pull the rug out from under someone, double-cross
Related Word: はしご (ladder), 外す (はずす, detach, take off, remove)