Bye Bye - S1.E2

'If you break a special thing, you can put it in the Bye Bye Box and it keeps it safe so you don't ever forget.'

Bing plays with a new orange balloon but when he bounces on it too enthusiastically, it pops. Bing is sad to lose his new toy, so Flop helps him put the balloon fragments in the Bye Bye Box, a memory box where things too broken to be fixed but too special to throw away are kept.