In an issue of InStyle magazine where they're asking celebs "what's hot?", Christine's answer was "laughter." There was some blah blah blah stuff, but then, underneath a killer picture of a barefoot Christina, were the words "Tickle time is a wonderful time at our house."
Yes, she was probably just referring to her child, but I like to think she was also on the receiving end more than a little. I no longer have the original magazine and the closest thing I've found online mangled her original quote. I'll keep digging as time allows.
Bandit