That's because they aren't involved in anything. When you get to your late 30s you can drift away from your friends - it's not that you aren't friends anymore - it's just that everyone is busy with work, home, family, etc. People mix with their work colleagues, their neighbours, community groups, other parents at the school if they have kids, people at sports groups, GAA etc.
Sue and Dylan don't seem to work, they don't seem to have hobbies apart from eating out, drinking and working out alone. They don't mix with anyone and they don't get involved in their local community.