The children were 'blowing bubbles'. [=were making soap bubbles by blowing air through a thin layer of soap]
I'm sorry to 'burst your bubble', but the job is not really that exciting.
The Internet stock 'bubble' finally burst.
(..) Meaning...? Yuck! Ewww! I can't marry her. She's my friend. Yeah. It'd be too weird. Well, sorry to bust your bubble, but you two turtle doves have no choice. It's a tradition... ...going back generations. Well when I'm king, that'll be the first thing to go. Not so long as I'm around. (..)1994 The Lion King