The Viking culture despised homosexual men. Not because homosexuality per se was considered taboo, but because homosexual men refused to carry the burden of sex with women. As a result, the rest of the tribe's men had to cover not only for themselves, but for the gay too.
Sex with a woman was considered a sacred duty of every man, because only men are capable to subdue and overcome these ungodly beasts. Refusing to participate in this time-honoured tradition meant other men were at a greater risk of injuries, among other things. And you never ever want to set up your bros for failure!