‘Sincere love’ cannot legitimise a prohibited practice. For example, even in the morally degenerative, secular, liberal society that we live in today, incest between brother and sister, mother and son or daughter and father are universally considered to be abhorrent. Claims of ‘sincere love’ do not legitimise such relationships.
In the same manner, homosexuality cannot be legitimized by claims of sincere love. Whereas man made norms are subject to change, the rules set down by God are immutable, eternal and based on a higher wisdom.