It's also a good idea to carry a small air freshener/body spray for outcalls to use just in case you get caught short yourself!
I was booked for a 2 hour outcall to a hotel. I'd been there about 10 minutes and was well into giving the guy a bj when I felt the unmistakeable rumble that signals a quick dash to the loo required. I thought "oh no" and tried my best to ignore it - I thought "ignore it, ignore it, it will go way". But it didn't go away. Several griping pains later I had to stop and make a dash for the bathroom - apologising on the way. I'd left it too long to stop and excuse myself with dignity! Once I'd made it safely to the loo I tried my best to make it as quiet as I could but as I'd held onto it for so long my body was determined to explode it out of me!
So it was obvious what I was doing in there! After what seemed like an eternity and wondering what the guy was thinking I was finally ready to exit the bathroom. I looked around desperately for something to spray (hopefully his deodorant) but there was none there! Luckily I'd brought some body spray with me but it was in my case (I'd grapped by bag on the way to the loo but left my case next the bed). I then had to go back into the room and retrieve my spray from the case whilst trying to make light of the situation saying something like "oops, sorry, this is so embarrassing... I shouldn't go in there for a while". Luckily, he saw the funny side and the rest of the booking went well.