Let`s have a look at the following idiom:

Like watching paint dry

If you watch something that is very long and boring, you can say it is like watching paint dry.

Examples

My girlfriend loved the Les Miserables movie, but I hated it. For me, it was like watching paint dry.

The chancellor's budget speech is on TV later. It'll be like watching paint dry!

I hate it when football is on the television, it's like watching paint dry.