Yes they are popular. I get them when I can but often they need to pee before they cum and can't do so at the end of the shoot which is when we tend to do them. It is a bit of a logistical thing. To get a decent shot you have to move the lighting into the bathroom where it is cramped, miirrors all over the place and not easy to shoot in. And it is hard to do this at the beginning of the shoot when the model is a bit nervous and not relaxed.