Originating from Litty Titty, this clever spinoff conveys the same meaning on a greater scale. It is an exclamation of excitement, or it is used in place of "extremely awesome".
Tanner: That party was so much fun. Seth's house is the best for throwing parties.
Jackson: Yeah, that was litty clitty.
Tanner: Tonight there is a party at Seth's house!
Jackson: Litty clitty!