at your peril
at (one's) own peril
Done with the foreknowledge or forewarning that there is implied danger, especially of loss of life, which one must accept as one's own responsibility. Those who skydive do so at their own peril.
(do something) at your (own) ˈperil(often used as a warning) at the risk of serious danger: People who go climbing in winter do so at their own peril. ♢ You go in Mike’s car at your peril. He’s a terrible driver.
See also: peril