Best definition
Wonderbra moment
The crushing realisation that everything is not entirely as it seems but you’re already committed, in exactly the same way

as a rat in a trap could be also be described as committed.

Dude1:”Just got a fantastic deal on a new phone, check it out! its like ten a month!”

Dude2:”That’s the introductory offer, after the first three months it’s fifty, for the next three years…”

Dude1:<Looks at phone, feels blood draining from face, has Wonderbra moment>