wife thinks that no one is going to want to have sex with her, how do I find a man?

that would really be up to her and her comfort level as well as communication between the 2 of you. It might be better that way for the first time even if you in the house just not in bed with them as long as you have the control to not bother them while they are "engaged" so to speak.
I agree that they have sex wherever they want, only that my wife is not quite sure what to do to take him to fuck
because it will be the first time that she will be with another man after we are not married
 
he will be far more comfortable if he is alone with her at least the first time, so will she, otherwise she well be nervous and worried about how you will react watching her cum her little pussy off on your friends superior dick
Not necessarily - he might find it a breach of friendship trust
 
She must tell the lover up front what she wants. He or she must fallow what she wants. He or she must not deviate from that. Rules