a) viagra/cialis will not make you have an erection if you are nt aroused. it simply keeps those fun little brain "holy shit" stress/new situation/etc chemicals from interfering.
b) if a guy im with cant get it up, i dont need to talk about it. we both it happened, move on. maybe we can go back to other things till he gets up again. if he can't, i nicely say it happens, no worries, and we move on.
c)seriously, get over the concept that it's not "genuine" if you take a little blue pill.