always use your own condom, dont listen to client wanting to use their own, incase they have been tampered with, for some sick crazy reason ( i.e heard about a story before in the states about a guy making loads of tiny needle pinprick holes in condoms and infecting woman he slept with, because he had caught h.i.v, and he was bitter and angry against women, he wanted to infect as many women as possible and make them all suffer, this was his form of punishment and justice for his predicament). never be trusting in this situation and cancel asap if he refuses to use yours.