(someone) is in stitches

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.

This phrase appears in these lessons: