Muck about

Stop mucking about and get on with your work!

Don't muck about with the video machine, or you might break it.

It was only a joke. We were only mucking about.

The only time I walk out on singin' is when there's muckin' about and youse don't take it serious.

Then he started stalling. In the end he mucked me about so much that I lost my patience and decided to nick the books from him.