There could be a variety of reasons why a man may like to live alone after marriage. Some possible reasons could include:
Personal preference: Some people simply prefer to live alone and have their own space and independence.
Relationship problems: If a man is experiencing relationship problems with his spouse, he may want to live alone to have time to think and work on the issues.
Differences in lifestyles: If a man and his spouse have different lifestyles and schedules, living separately may allow them to have more freedom to pursue their own interests.
Career demands: If a man's career requires a lot of travel or long hours, he may prefer to live alone to have more control over his schedule.
Financial reasons: If a man is financially independent and can afford to live on his own, he may choose to do so rather than live with a spouse.
After marriage if a person is want to live alone its may be a psychological effect on man.may be he has no understanding with her wife. Marriage is a strong relationship between man and woman.
After marriage some men tend to live alone not because they are selfish sometimes may their place of work is far from their home or they might be doing different jobs which will force him and his family to stay apart.