You could always keep a roll of paper towels near by, so when you're ready, you can grab one and then no mess or, who ever is giving the handjob, could always catch it in their mouth.

shadowy

Check out some of the 'sticky' threads in the 'pleasing him' section. (such an ironic term) It doesn't neccesarily have to be awkward, but simply a continuation of the act. If you discuss it together openly then the problem often goes away and you may suddenly find that you're doing even more fun things.

That goes for most things actually.