family-phobe
A person who fears that getting married, having children or engaging in family relationships will suck the fun and excitement out of their life. These people tend to believe that such relationships would restrict them from chasing their dreams, reaching their goals and living life the way they choose.
Family-phobes put off marriage until they have chased all their dreams. They put off having children until they have met all their goals. Family is something they get around to when there's nothing left to do. Family-phobes tend to be self absorbed. Their life revolves around their own entertainment, education, career, or cause.