“I was in stitches the whole show.”
You went to see a play, and it was really funny. You're recommending the play to a friend, and you describe how funny it was.
I was in stitches the whole show.
When someone is "in stitches" it means that they are laughing a lot, and can't stop laughing:
A: How was the comedy show?
B: Oh man, I was in stitches!
If something is just a little funny, you don't use this phrase. You can say something else, like:
It was funny.
I got a good laugh out of it.
The word "stitches" comes from a medical treatment. When someone gets a large cut, a doctor will sew the wound to keep it closed. Sewing together a wound is known as "giving (someone) stitches". It's a little hard to connect "stitches" to laughing, but you can imagine laughing so hard that your stomach starts to hurt as if you had stiches in it.
A "show" can mean a lot of things:
- a television show
- a musical performance
- a play
- a comedy performance
You can use "show" like this:
Hey, are you coming to my show?
We're going out to see a show tonight.
It was a good show.
What are you doing after the show?