That's What She Said Meaning

(US, humorous, idiomatic) A joking retort, intended to draw attention to a previous statement which has the potential for a risqué double entendre.

Example: 2008, Ron Fletcher, "In the Internet Age, a few lessons about bad jokes, good taste," Boston Globe, 2 Mar. (retrieved 7 Apr. 2009):
  Some seemed bored and irritated by the priapic yahooism and overwillingness of peers to read a sexual double entendre into the most innocuous remark. "No matter what you say," said one student, "someone is going to respond with ‘That's what she said.’ "
2008, Rick Broida, "Quick Tip: Increase the Font Size in Your Browser," PCWorld.com, 24 Nov. (retrieved 7 Apr. 2009):
  So this morning we pulled up a pumpkin-pancake recipe on the kitchen laptop. Just one problem: My wife couldn't read it from where she was mixing. "Can't you make it bigger?" she asked. (Go ahead, insert your own "that's what she said" joke here. No class.)