Now, if they were biblical and didn't support, Homosexuality, they would realize that (and so would the Canadian government ) that:

1 Corinthians 7
2 But because of immoralities, let each man have his own wife, and let each woman have her own husband.
3 Let the husband fulfill his duty to his wife, and likewise also the wife to her husband.
4 The wife does not have authority over her own body, but the husband does; and likewise also the husband does not have authority over his own body, but the wife does.---NASB