Used to remark on something that sounds dirty. Similar to 'that's what she said' only not childish and outdated. Usually used with double entendres.
âWhenever I feel blue, I start breathing again.â Woof.
â L. Frank Baum
When you fancy someone who is in a significant position of authority over you and has the ability to ruin or end your life if they ever found out. Since actually doing anything would blow your cover you never do anything about it, and so you have so little to gain but so much to lose by having a danger crush. The objective of this is to prevent anyone from ever finding out, which makes it even more dangerous and exciting for you.
So I see you're spending a lot of time with the daughter of that crack-dealing pimp, he's gonna kill you if he ever finds out. B: Yeah. She's my danger crush.