goof on (someone or something)
To mock or tease someone or make fun of something. Sarah's a very sensitive kid, so don't goof on her.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
goof on someone
Inf. to tease or kid someone. I don't believe you. I think you're just goofing on me.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
Make fun of, mock, as in He was always goofing on his little brother. [Slang; mid-1900s]
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.