Marriage isn't a religious institution by default, moron.
The best conditions for child rearing are usually given by a stable, two-parent family. Since child rearing is massively important to society, the government should at least make some effort towards encouraging stable, two-parent families.
So yes it should be formalised to the extent that formalised partnerships get certain tax breaks.
Because that's the only way you get stds, right?STD is only spread by gays? lol
yeah there is enough butt fucking going on with straight couples. Look at anal porn.