Kidding Aside Meaning

(speech act, idiomatic) Used to attempt to make a serious point in a jocular conversation.

Example: 2004, Lillie Weiss, Therapist's guide to self-care, page 43:
  Phyllis Diller used to joke that it is important to be nice to your children because they ultimately decide which nursing home to place you in! Kidding aside, if you don't take the time for children and family […]