Yeah, we like to joke around and make faces and try to get the others to laugh while playing, as long as it doesn't affect the sound, but I had a bass player who used to get a little carried away about messing with us. One night we were playing a gig and I was in the middle of a guitar solo, eyes closed, really getting into it and all of a sudden, my sound went from overdrive to clean. I looked up and my bass player was laughing as he had stepped on my pedals and changed them. I told him not to be doing that because it messed up our sound. Later, he did it again while I was in the midst of a solo. I said, "Man, that's not cool. Don't be screwing up the sound." Well, later I was doing another solo and pretended to have my eyes shut while actually watching him out of the corner of my eye. As he stepped over to step on my pedal again, I reached out, grabbed one of his tuning keys and detuned his bass. He never messed with my pedals again. 
