@MichaelaH That's flows much better in my opinion You may want to lose the line "Flip didn't wait etc" and maybe have something like:
"Ohhh, ohhh do you know this one?" Flip asked "Why don't bears like fast food?"
Berry started to think, but before he could answer-
"Because they can't catch it!" Flip blurted out as he splashed around in a fit of giggles.
That's only an idea anyway, I'm not the best at writing so it's totally what you're happy with and what you think flows well