I wouldn't recommend doing it with a friend. Looking past the initial hurrah, in time you may want to slacken off with this particular friend, and he may want more of your time. That could lead to threats of exposure, etc. that might prove to be an embarrassment to you and to your husband.
With so many strangers willing to get between your legs, why not pick someone you and your husband are BOTH comfortable with in the stranger's company, without the possibility of revelations to your friends?