You two need to sit down and talk about it. Sex is a large part of a marriage. I have been married 7 years and have a 6 year old. Bringing in a friend is very bad. if there is issues the friend will make it worse. as suggested above, make a list of fantasies. if she has no drive seek a dr, however 30s is usually when they pick up. again, I can't stress how important communication is here. Just talk about it, get prefessional help if need be. this issue could be the start of major problems...