I don't understand why Ake thinks that permitting same-sex marriage would cause health problems.

Surely, if his proposal that gay men, in particular, carry a higher-than-normal risk of HIV and other STD infections because of a supposed 'promiscuous' lifestyle is to be believed, commitment to a single partner through marriage would cause a reduction of that risk?

In which case, on that basis alone, isn't single-sex-marriage a cause worth fighting for?

Of course, that isn't the only basis to be applied, fairness and equality are the most important drivers, but I find objections on the grounds of 'health and societal grounds' somewhat illogical.