Vikings really didn't care much who or what you had sex with. However, they were required by law to form families and produce children; it was considered a duty to society. Such a law is not really surprising considering the attrition rate of a warrior culture such as theirs. If you didn't want to start a family you could be charged with "fleeing from vagina" (or "fleeing from noodle" if you're a woman). So there were no gay families or gay marriages in Viking society, but no one cared who you had sex with for fun. As far as the law was concerned marriage and the family unit was strictly a matter of producing future warriors. Viking law also demanded you be a productive member of society by learning a craft and producing something of value to society. People who didn't were kicked out into the wilderness to fend for themselves. "Charity" was not in the Viking vocabulary.
