Always tell someone where you are going too and make sure you have an escape plan if things don't work out or get a bit uncomfortable (ie. enough cash for a taxi, enough credit on your phone, enough battery too!).
Always meet in a public place & somewhere familiar so you have your bearings as well.
Being a single fem meeting a couple, it's important (well I think it is) to discuss what you both want before gettin down to it - often it ends up that the single fem is fulfilling the couple's fantasy & not their own as well!
Just my two bobs worth...
