The phrase "You slay me" is slang and it means to overwhelm, as with laughter or love.

It is used in response to something funny someone has said or done.
person 1 says or does something funny.
person 2 in response can only sum up the amazing funniness that has occured with the phrase "you slay me," signifying total appreciation of the funny event and deeming it hilarious and worthy of acknowledgement.
by hownowbrowncow00 February 7, 2011
Get the you slay me mug.