"I'm so nervous about tonight i have 'Butterflies in my stomach'."
metephor
Yes, "butterflies in stomach" is indeed an idiom. It describes the fluttery, nervous feeling one experiences in anticipation or anxiety, such as before a performance or important event. The phrase metaphorically relates the sensation to the light, fluttering movements of butterflies. It captures the emotional state rather than any physical condition.
It's an idiom meaning that you feel nervous, because when you're nervous it feels like something in your stomach is fluttering or twisting.
He told me I had won, but I thought he was pulling my leg.
Let's meet at a restaurant and get a bite to eat.
My sister always "cracks me up" with her jokes.
I cannot find a firm origin for this saying. Evidently people once believed that the nervous sensation might be caused by something you had eaten.
John loved to dance and would do so at the drop of a hat.
The victim was badly injured, so a sentence of community service is no more than a slap on the wrist.
when i went back to my apartmemt their was a big cry wolf in room 208.
You're going to be broke soon if you don't get job and stop spending money.
As my mom would say......... Early Bird gets the worm!