laugh (oneself) silly
To laugh extensively, perhaps to a point of giddiness. I love getting together with my childhood friends because we always seem to laugh ourselves silly.
laugh yourself silly (or sick)
laugh uncontrollably or for a long time.— yourself silly
be unable to act rationally because of doing something to excess. 1998 Time Out N.Y. Drink yourself silly at the long bar or chow down at the large tables in the back.