Speaking for the audience---- play forever if you can, and take a pee break if you must, but be honest about how long the break will be. I like to know how long I have for my pee break, and I don't want to miss a minute of good music. Lines in the ladies room-- uh oh!On the other hand, I may have to get home, and if the break is going to run very long, I would rather know that up front. Otherwise, I'm sitting there staring at my watch wondering if you will ever come back, and then finally decide to leave after a half hour when, if I had known, I would have just left when the set ended, happy as a clam with what I had heard.
Now this is all somewhat tongue in cheek, because now I play a bit here and there and it is very different on the mic side of the equation. It's hard work, playing, and my point is, your audience will not really know that and so they need to be catered to a bit.
Have fun with it!!!!
~S~