get (something) off (one's) chest
To reveal or discuss something that has caused one emotional discomfort and that one has repressed, kept hidden, or neglected to discuss earlier. I'm sorry but I just have to get something off my chest. How could you treat me like that last night?
get something off one's chest
to unburden oneself; to confess something; to criticize or make a personal complaint to someone. You will feel better if you get it off your chest. I have to get this off my chest. I'm tired of your rudeness to me!
get (something) off (one's) chest
To vent one's pent-up feelings.
get (something) off one's chest, to
To unburden oneself of a secret, criticism, worry, or the like. The London Daily Chronicle of 1902 is cited by the OED: “To deliver a message to the world or to express the individual personality—to ‘get it off your chest’ is the horrid vulgar phrase.”