I do a job that is busy and requires a lot of concentration and attention to detail at times.
Don't want to say what incase colleagues are on here etc.
I was working on a task when a colleague came and deliberately distracted me as a joke.
Imagine i was decorating a cake precisely, this person came up behind me and was saying to look over there.
I carried on with what I was doing and zoned out because I wasn't sure that he was talking to me and I was concentrating hard. He proceeded to say "look, over there" a couple more times, then tapped me on the shoulder and pointed and said "look what is that". Completely oblivious to the joke, I looked. He pretended he was going to eat the cake but ended up knocking it over, meaning I had to start again.
This is something that has happened a number of times (not actually knocking it over), by the 20th time the joke gets old and the distraction is very unwelcome.
Anyhow, I just looked blankly at this guy and said that's not funny, he seemed to take offence that I didn't fall over laughing at his joke.