What your husband is experiencing is commonplace. If he is nervous and worried about performing with a new women then it tends to become a self fullfilling prophesy. I have been actively in the lifestyle for 7 years and still get nervous and have problems sometimes with new people although I seldom have a problem with women that I have known for years and am very comfortable with. The only thing I can suggest is to be honest with the new partner. A lot of women are very understanding and don't have a problem with oral if that's what works. If he doesn't spend all his time worrying about it he is less likely to have a problem in the first place. After he has been in the lifestyle for a while he will be more comfortable in general and less likely to have issues. I don't know if Viagra would help or not. It's never really worked for me.