Script (guión): Idioms, ‘butterflies in your stomach’. If you are nervous before an important event or occasion and your stomach feels a little unusual we call this having butterflies in your tummy or stomach. For example, two twin brothers on the morning of their first day at school. ‘I feel nervous mum I've got butterflies.’
‘Oh that's perfectly natural son, where's your brother?’
‘He's still on the toilet.’