Having spent my working life in education, we often, (in England) employed lecturers who lived in one city during the week and went home at weekends. Most of these lecturers, both male and female, end up with a friendship circle in the town in which they work, often leading to an affair.
Loneliness and boredom, are issues, as people we like company, and find comfort where we are.
It is not about being as expat, it is about the need for affection.