If it's Uk 8 ball it's not a problem.

If its US 8, for example on the bottom left corner, then simply hit the white of the top cushion to hit the colour at an angle so that it goes into the top cushion then goes into the bottom middle pocket.

Simple

Or keep playing untill one of you needs the loo and cant hold it in any longer

Yeah in uk8 if your on the black and someone does this and gives you 2 shots you can hit there colour ball to hit the black in. Us8 some of these games i've been in and they are pretty fun.

yea i love the occasional tactical battle, gets the cogs turning